Imaging apparatus capable of recognizing photographic scene and method for the same

ABSTRACT

To output stable results as necessary when recognizing scenes with a camera. Unless the result of scene recognition can be stabilized, an output result will confuse the user. In consideration thereof, by combiningly performing processing for determining what type of scene a particular scene is and processing for monitoring whether or not a change has occurred from a recognized scene, it is now possible to perform scene recognition in an accurate and stable manner.

This application is a continuation of U.S. application Ser. No.12/509,047, filed Jul. 24, 2009, which claims priority to JP2008-192281, filed Jul. 25, 2008, and JP 2008-195273, filed Jul. 29,2008, each of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus including aphotographic scene recognition function.

2. Description of the Related Art

In Japanese Patent Application Laid-Open No. 2003-244530, whether or notan actual photographic scene is appropriate with respect to a setphotographic mode is judged based on a digital image signal loaded via aCCD or on an EV value. When the photographic mode is appropriate, adigital camera performs photographic processing in the photographic modeand records information on the photographic mode on a header portion ofimage data. When the photographic mode is inappropriate, the digitalcamera confirms with an operator as to whether or not photography is tobe carried out in the set photographic mode and transitions tophotographic processing, and either confirms with an operator as towhether or not the photographic mode information is to be recorded onthe header portion of image data or records standard photographic modeinformation.

Japanese Patent Application Laid-Open No. 2003-344891 discloses aphotographing mode autoconfiguration camera that sets a photographingmode of the camera based on output information from a face recognizingdevice and a state detecting device. The camera according to JapanesePatent Application Laid-Open No. 2003-344891 automatically configures acamera photographing mode (shooting mode) based on output information onsubject movement, imaging magnification, or subject distance. Here,photographic mode settings include Tv value, Av value, program, diagram,exposure (dimming correction), strobe flashing, zoom AF mode, paper feedmode, photometry mode, and the like.

SUMMARY OF THE INVENTION

“Photographic mode check processing” (S13 in FIG. 2) according toJapanese Patent Application Laid-Open No. 2003-244530 is always inworking condition. Therefore, the processing becomes less efficientcompared to the case where the processing is performed when necessary.In addition, “photographic mode autoconfiguration” (step 112 in FIG. 4)according to Japanese Patent Application Laid-Open No. 2003-344891 is aonce-only operation performed after a shutter button is pressed halfway.Therefore, an appropriate photographic mode is not necessarily stablyset in response to photographic scenes that are likely to changeconstantly.

An object of the present invention is to output stable results asnecessary when recognizing scenes with a camera.

An imaging apparatus according to a first aspect of the presentinvention comprises: an information acquiring device which acquiresphotographic information which is information on a photographic scene; areference information registering device which registers referenceinformation which is set based on the photographic information; a scenechange determining device that determines whether or not the scene haschanged based on the reference information stored in the referenceinformation registering device and the photographic information acquiredby the information acquiring device, a scene recognizing device whichrecognizes a scene based the photographic information acquired by theinformation acquiring device when it is determined, by the scene changedetermining device, that a scene is changed; and a control device whichperforms at least one of display control, photographic control, signalprocessing control, and information recording control in response to ascene recognition result by the scene recognizing device.

In the imaging apparatus, the scene recognition device can update thereference information registered in the reference informationregistering device based on the photographic information correspondingto the scene recognition result.

In the imaging apparatus, the information acquiring device can acquireat least one of: face detection result information indicating whether ahuman face exists in the photographic scene; subject distanceinformation on a subject distance; and photometric information onbrightness of a subject.

Otherwise, in the imaging apparatus, the information acquiring devicecan acquire, as the photographic information, two or more of: facedetection result information indicating whether a human face exists in aphotographic scene; subject distance information on a subject distance;and photometric information on brightness of a subject, and the scenechange determining device can determine whether the photographic scenehas changed or not based on the photographic information acquired by theinformation acquiring device and the reference information correspondingto the photographic information.

In the imaging apparatus, the scene change determining device caninclude a weight setting device which respectively weights, byinformation type, the two or more of information acquired by theinformation acquiring device and the reference information correspondingto the two or more of information.

In the imaging apparatus, the scene change determining device cancomprise: a single scene change determining device which successivelydetermines the occurrence/nonoccurrence of scene change based on thereference information stored in the reference information registeringdevice and the photographic information acquired by the informationacquiring device; a scene change history record registering device whichregisters, as a scene change history record, single scene changedetermination results by the single scene determining device; and atotal scene change determining device which determines whether thephotographic scene has changed or not based on the scene change historyrecord.

In the imaging apparatus, the scene recognizing device can comprise: asingle scene recognizing device which executes, for a predetermined timeperiod or a predetermined times, single scene recognition forrecognizing the photographic scene based on the photographic informationacquired by the information acquiring device; a scene recognitionhistory record registering device which registers, as a scenerecognition history record, a history of single scene recognitionresults by the single scene recognizing device; and a total scenerecognizing device which executes total scene recognition forrecognizing the photographic scene based on the scene recognitionhistory record registered in the scene recognition history recordregistering device.

In the imaging apparatus, the total scene recognizing device can detecta photographic scene with a greatest frequency from the scenerecognition history record, and recognize the photographic scene withthe greatest frequency as the total scene recognition result.

In the imaging apparatus, the total scene recognizing device detects aplurality of photographic scenes with the greatest frequency aredetected, the total scene recognizing device can recognize a most recentphotographic scene with the greatest frequency as the total scenerecognition result.

In the imaging apparatus, the total scene recognizing device caninclude: a weight setting device which weights each single scenerecognition result in the scene recognition history record registered inthe scene recognition history record registering device such that thegreater weight is assigned to the newer single scene recognition result;and a calculating device which calculates a cumulative score for eachsingle scene recognition result weighted by the weight setting device,and the total scene recognizing device can determine a single scenerecognition result with the highest cumulative score calculated by thecalculating device, as the total scene recognition result.

The imaging apparatus can further comprise a shutter button whichinstructs photometering and ranging for primary exposure when halfwaypressed and instructs primary exposure when fully pressed, wherein anumber of single scene recognition results before the shutter button ishalfway pressed and a number of single scene recognition results afterthe shutter button is halfway pressed are separately set in the scenerecognition history record registered in the scene recognition historyrecord registering device.

The imaging apparatus can further comprise a photographic informationhistory record registering device which registers, as a photographicinformation history record, a history of the photographic informationacquired by the photographic information acquiring device, wherein thescene recognition device comprises a total scene recognizing devicewhich performs total scene recognition for recognizing the photographicscene based on the photographic information history record registered inthe history record registering device.

The imaging apparatus can further comprise a shutter button whichinstructs photometering and ranging for primary exposure when halfwaypressed and instructs primary exposure when fully pressed, wherein anumber of units of photographic information before the shutter button ishalfway pressed and a number of units of photographic information afterthe shutter button is halfway pressed are separately set in thephotographic information history record registered in the photographicinformation history record registering device.

The imaging apparatus can further comprise a photographing mode settingdevice which sets a photographing mode depending on the scenerecognition result by the scene recognition device, wherein the controldevice performs the photographic control according to the setphotographing mode.

The imaging apparatus can further comprise a shutter button thatinstructs photo-metering and ranging for primary exposure when halfwaypressed and instructs primary exposure when fully pressed, wherein afterthe shutter button is pressed halfway, the information acquiring deviceacquires only information indicating a subject distance for primaryexposure and information on the brightness of a subject for primaryexposure.

The imaging apparatus can further comprise a selecting device whichselects a timing to perform scene recognition of the photographic scenefrom upon a determination of scene change or at a predetermined cycle;and a cycle setting device which sets the predetermined cycle when thescene recognition is to be performed, wherein when the selecting deviceselects to perform the scene recognition of the photographic scene atthe predetermined cycle, the scene recognition device performs the scenerecognition of the photographic scene based on the photographicinformation acquired by the information acquiring device at thepredetermined cycle set by the cycle setting device instead of upon thedetermination of scene change by the scene change determining device.

In the imaging apparatus, the predetermined cycle to be set by the cyclesetting device can be a preset cycle or a cycle arbitrarily settable bya user.

According to a second aspect of the present invention, an imaging methodcomprises: acquiring photographic information which is information on aphotographic scene; recognizing a scene from the acquired photographicinformation; storing reference information which is set based on thephotographic information corresponding to the scene recognition result;determining whether the scene has changed or not from based on thestored reference information and the acquired photographic information;recognizing the scene based on the photographic information when it isdetermined that the scene has changed; and performing at least one ofdisplay control, photographic control, signal processing control, andinformation recording control in response to the scene recognitionresult.

In the imaging method, the recognizing of a scene can include: a singlescene recognizing step for recognizing the photographic scene based onthe acquired photographic information; a scene recognition historyrecord registering step for registering a predetermined number of newestsingle scene recognition results recognized in the single scenerecognizing step as a scene recognition history record in a historyrecord registering device; and a total scene recognizing step forrecognizing the photographic scene based on the scene recognitionhistory record registered in the scene recognition history recordregistering device.

Otherwise, in the imaging method, the recognizing of a scene caninclude: a photographic information history record registering step forregistering a predetermined number of newest units of photographicinformation as photographic history record in a photographic informationhistory record registering device; and a total scene recognizing stepfor recognizing the photographic scene based on the photographicinformation history record registered in the photographic informationhistory record registering device.

According to the present invention, processing for determining what kindof scene a particular scene is, and processing for monitoring whether ascene change has occurred compared to a scene when the recognition hasbeen performed are combinedly operated. Moreover, the determination of akind of scene (scene recognition) is performed when the scene haschanged. This enables scene recognition to be performed in an accurateand stable manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram showing a configuration of a digitalcamera;

FIG. 2 is a flowchart of scene recognition main processing according toa first embodiment;

FIG. 3 is a flowchart of a frame change check;

FIG. 4 is a flowchart of a photometric value change check;

FIG. 5 is a flowchart of a focus position change check;

FIG. 6 is a flowchart of a face presence/absence change check;

FIG. 7 is a flowchart showing details of scene recognition;

FIG. 8 is a flowchart of a scene judgment subroutine (portraitjudgment);

FIG. 9 is a flowchart of a scene judgment subroutine (landscapejudgment);

FIG. 10 is a flowchart of a scene judgment subroutine (night scenejudgment);

FIG. 11 is another example of a flowchart of a scene judgment subroutine(night scene judgment);

FIG. 12 is a flowchart of a scene judgment subroutine (macro judgment);

FIG. 13 is a flowchart showing scene recognition processing according tothe first embodiment of the present invention;

FIG. 14 is a diagram schematically showing total scene recognitionprocessing;

FIG. 15 is a diagram schematically showing total scene recognitionprocessing;

FIG. 16 is a diagram showing an example of a scene judgment resultdisplay;

FIG. 17 is a flowchart of a frame change check according to a secondembodiment;

FIG. 18 is a table showing a relationship between weightsE_AUTOSP_FRAME_CHECK1 to 3 corresponding to first to third frame changechecks and “change_measure” values corresponding to theoccurrence/nonoccurrence of changes in the first to third frame changechecks;

FIG. 19 is a flowchart of scene recognition main processing according toa third embodiment;

FIG. 20 is a diagram showing an example of frame change history records;and

FIG. 21 is a flowchart of scene recognition main processing (scenechange recognition/cyclic recognition concomitant) according to a fourthembodiment.

FIG. 22 is a flowchart showing total scene recognition processing(before S1) according to a second embodiment of the present invention;

FIG. 23 is a flowchart showing total scene recognition processing(during S1-on) according to the second embodiment of the presentinvention;

FIGS. 24A and 24B are diagrams schematically showing total scenerecognition processing (before S1) according to a third embodiment ofthe present invention;

FIGS. 25A and 25B are diagrams schematically showing total scenerecognition processing (during S1-on) according to the third embodimentof the present invention;

FIG. 26 is a flowchart showing total scene recognition processing(before S1) according to the third embodiment of the present invention;

FIG. 27 is a flowchart showing total scene recognition processing(during S1-on) according to the third embodiment of the presentinvention;

FIG. 28 is a diagram schematically showing total scene recognitionprocessing according to a fourth embodiment of the present invention;

FIG. 29 is a flowchart showing total scene recognition processingaccording to the fourth embodiment of the present invention;

FIG. 30 is a diagram schematically showing total scene recognitionprocessing (before S1) according to a fifth embodiment of the presentinvention;

FIG. 31 is a diagram schematically showing total scene recognitionprocessing (during S1-on) according to the fifth embodiment of thepresent invention;

FIG. 32 is a flowchart showing total scene recognition processing(before S1) according to the fifth embodiment of the present invention;

FIG. 33 is a flowchart showing total scene recognition processing(during S1-on) according to the fifth embodiment of the presentinvention;

FIG. 34 is a diagram schematically showing total scene recognitionprocessing (before S1) according to a sixth embodiment of the presentinvention;

FIG. 35 is a diagram schematically showing total scene recognitionprocessing (during S1-on) according to the sixth embodiment of thepresent invention;

FIG. 36 is a flowchart showing total scene recognition processing(before S1) according to the sixth embodiment of the present invention;and

FIG. 37 is a flowchart showing total scene recognition processing(during S1-on) according to the sixth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 is a schematic block diagram showing a configuration of a digitalcamera 1 according to the present invention. A digital camera 1 convertsimage data acquired through photography into an Exif-format image fileand records the Exif-format image file into a recording section 70 suchas an external recording medium that is attachable/detachable to a mainbody.

A manipulation system of the digital camera includes: a manipulationsection 11 having an operating mode switch, a menu/OK button, azoom/upward/downward arrow lever, a leftward/rightward arrow button, aBack (return) button, a display switching button, a shutter button, apower switch, and the like; and a control circuit 74 that interpretscontents of manipulations performed on the manipulation section 11 andcontrols the respective sections. The control circuit 74 includes: a CPU75 which performs information processing; a ROM 68 on which are recordedprograms defining information processing, firmware, constants such asthresholds used when performing various judgments with the programs, andthe like; and a RAM 69 storing variables, data, and the like necessaryfor information processing.

A lens 20 includes a focusing lens and a zoom lens. The lens 20 ismovable in the direction of an optical axis by a lens driving section51. The lens driving section 51 controls movement of the focusing lensor the zoom lens based on either focusing lens driving amount dataoutputted from the CPU 75 or manipulation amount data of thezoom/upward/downward arrow lever included in the manipulation section11.

In addition, an aperture 54 is driven by an aperture driving section 55including a motor and a motor driver. The aperture driving section 55adjusts an aperture diameter based on aperture value data outputted froman AE/AWB processing section 63.

An image pickup device 58 such as a CCD or a CMOS is disposedposteriorly to an imaging optical system including the lens 20 and theaperture 54. The image pickup device 58 has a photoelectric surface onwhich a large number of light receiving elements are arrangedtwo-dimensionally. A subject light passed through the optical system isformed on the photoelectric surface to be subjected to photoelectricconversion. A microlens array for collecting light to each pixel and acolor filter array in which filters of the respective colors of R, G,and B are regularly arranged are disposed anteriorly to thephotoelectric surface. The image pickup device 58 outputs, line by line,electrical charges accumulated per pixel as serial analog photographicsignals in synchronization with a vertical transfer clock and ahorizontal transfer clock supplied from an image pickup device controlsection 59. The period of time over which an electrical charge isaccumulated in each pixel or, in other words, an exposure time isdetermined by an electronic shutter driving signal provided from theimage pickup device control section 59. In addition, a gain of the imagepickup device 58 is adjusted by the image pickup device control section59 so that analog photographic signals of a predetermined size can beacquired.

An analog photographic signal loaded from the image pickup device 58 isinputted to an analog signal processing section 60. The analog signalprocessing section 60 includes a correlated double sampling (CDS)circuit that removes noise from an analog signal and an auto-gaincontroller (AGC) that adjusts the gain of the analog signal.

An A/D converting section 61 converts an analog image signal processedby the analog signal processing section 60 into digital image data. Theimage data converted into a digital signal is CCD-RAW data having R, G,and B concentration values per pixel.

The control circuit 74 generates a timing signal and inputs the timingsignal to the image pickup device control section 59 so as tosynchronize: a manipulation of the shutter button included in themanipulation section 11; the loading of an electrical charge by theimage pickup device 58; and processing performed by the analog signalprocessing section 60.

A flash control section 73 emits a flash 24 configured by a strobedischarge tube and other circuits during photography (when the shutterbutton is fully pressed). Specifically, when the flash emission mode isset to “flash on”, the flash 24 is turned on in order to make the flash24 emit light during photography. On the other hand, when the flashemission mode is set to “flash off”, emission of the flash 24 duringphotography is prohibited.

The control circuit 74 performs photometry by detecting a luminance ofan image signal generated by the image pickup device 58. Upon receivinga photometry result indicating that the luminance of field is low, thecontrol circuit 74 instructs a fill light control section 25 to causefill light to be irradiated from a fill light emitting section 26configured by an LED or the like.

Respective image data (CCD-RAW data) of R, G, and B outputted from theA/D converting section 61 is subjected to white balance (WB) adjustment,gamma correction, and YC processing by a digital signal processingsection 65. Processed image data is written into a memory 66.

The digital signal processing section 65 is provided with a photometrysection 46. The photometry section 46 receives Y signals for one screenfrom the A/D converting section 61. The photometry section 46 integratesthe received Y signals for each of blocks (e.g., 64) produced byvertically and horizontally equally splitting into a predeterminednumber of blocks (e.g., 8), a desired area within an imaging plane ofthe image pickup device 58 such as an area in the vicinity of the centerof the imaging plane, a face detection area, or the entire imagingplane. An integrated luminance value of each block is sent to the CPU 75as a photometry result. During AE control, the CPU 75 performs knownarithmetic processing on the luminance integrated values based on apredetermined algorithm to determine a correct exposure (aperture value,shutter speed).

The memory 66 is a work memory to be used when performing variousdigital image processing (signal processing), to be described later, onimage data. For example, an SDRAM (Synchronous Dynamic Random AccessMemory) that performs data transfer in synchronization with aconstant-cycle bus clock signal is used as the memory 66.

A display section 71 is provided for displaying image data successivelystored in the memory 66 after a photographic mode is set until an actualphotography instruction is issued as live views on, for example, aliquid crystal monitor (not shown), and for displaying image data savedin the recording section 70 during a replay mode on the liquid crystalmonitor. The live views are to be photographed by the image pickupdevice 58 at a predetermined interval while the photographic mode isbeing selected. The live views are images which are sequentiallydisplayed on the display section 71 based on image signals representingsubjects to be photographed captured by the image pickup device 58 atpredetermined time intervals while the photographing mode is beingselected so that a user can recognize an angle of view and situation inreal time.

The pre-actual photography AF processing section 81 determines aphotographic condition based on the live views successively supplieduntil the shutter button is pressed halfway. In other words, thepre-actual photography AF processing section 81 detects a focus positionbased on the live views, and outputs focusing lens driving amount data.Conceivable methods of detecting a focus position include a passivemethod in which an in-focus position is detected by taking advantage ofthe characteristic that the contrast of an image increases in a focusedstate. That is, the pre-actual photography AF processing section 81extracts high frequency components from the live view, and integratesthe high frequency components within an entire image or within an area(the center portion, a face detection area or the like) of a specificportion of the image to obtain an AF (in-focus) evaluated value. A localmaximum point of the obtained AF evaluation value is searched across thelens driving range, whereby a lens position at which the local maximumpoint is obtained is determined as the in-focus position.

An AF processing section 62 and the AE/AWB processing section 63determine a photographic condition based on a pre-image. A pre-image isan image represented by image data stored in the memory 66 as a resultof the CPU 75, upon detecting a half-press signal generated when theshutter button of the manipulation section 11 is pressed halfway, causesthe image pickup device 58 to execute pre-photography.

The AF processing section 62 detects a focus position based on apre-image and outputs focusing lens driving amount data (AF processing).Conceivable methods of detecting a focus position include theabove-described passive method in which an in-focus position is detectedby taking advantage of the characteristic that the contrast of an imageincreases in a focused state.

The AE/AWB processing section 63 measures a subject luminance based on apre-image, determines an aperture value, a shutter speed and the likebased on the measured subject luminance, and determines the aperturevalue data and the shutter speed data as an exposure set value (AEprocessing). Based on image data obtained by primary exposure performedin response to the shutter button being fully pressed, the AE/AWBprocessing section 63 determines a white balance correction amount ofthe image data (AWB processing).

Exposure and white balance can be set by manual manipulation by a userof the digital camera 1 when the photographic mode is set to manualmode. In addition, even when the exposure and the white balance are setautomatically, the user is able to manually adjust the exposure and thewhite balance by issuing an instruction from the manipulation section 11including the menu/OK button.

A photographic condition corresponds to a scene recognition result SR tobe described later. For example, if the scene recognition result SR is anight scene, ISO sensitivity may be set to 80 and the shutter speed to1/1.6 seconds. Alternatively, if the scene recognition result SR ismacro, the aperture diameter is opened and emission of the flash 24 isprohibited. The searching of an in-focus position preferably proceedsfrom a near position (Near side) as a starting point to a far position(INF side). Alternatively, if the scene recognition result SR islandscape, “average photometry” is used as a photometry mode and thephotometry section 46 is arranged to perform divisional photometry.Alternatively, if the scene recognition result SR is a portrait, the AFprocessing section 62 assumes a calculation area for which an AFevaluation value is to be calculated (AF evaluation value calculationarea) as a face area detected by a face detection processing section 80.If the scene recognition result SR is AUTO, photograph conditions suchas the shutter speed and aperture value are automatically set.

Image data of an actual image is subjected by the digital signalprocessing section 65 to image quality correction processing such asgamma correction, sharpness correction, and contrast correction, as wellas YC processing in which CCD-RAW data is converted into YC data made upof Y data that is a luminance signal, Cb data that is a bluecolor-difference signal, and Cr data that is a red color-differencesignal. An actual image refers to an image formed by image data loadedfrom the image pickup device 58 during actual photography that isexecuted when the shutter button is fully pressed and stored in thememory 66 via the analog signal processing section 60, the A/Dconverting section 61, and the digital signal processing section 65.While an upper limit of the number of pixels of an actual image isdetermined by the number of pixels (pixel count) of the image pickupdevice 58, for example, the number of recording pixels may be changed bysettings such as fine and normal. Meanwhile, the numbers of pixels of alive view and a pre-image are smaller than that of the actual image and,for example, a live view and, a pre-image are to be loaded with around1/16 of the number of pixels of the actual image.

In addition, the digital signal processing section 65 calculates theluminance of a face area in the actual image when the amount of emissionof the flash 24 is set smaller than during normal photography andperforms processing for adjusting the luminance of the face area to apredetermined threshold Th1 when the luminance is smaller than thethreshold Th1.

The digital signal processing section 65 performs compression processingin a compression format such as JPEG on image data of an actual imagesubjected to correction/conversion processing to generate an image file.A tag storing collateral information such as the time and date ofphotography is added based on the Exif format or the like to the imagefile. In addition, during replay mode, the digital signal processingsection 65 reads out a compressed image file from the recording section70 and performs expansion processing thereon. The expanded image data isto be displayed on an external liquid crystal monitor by the displaysection 71.

The ROM 68 stores various constants to be set by the digital camera 1,programs to be executed by the CPU 75, and the like. The RAM 69temporarily stores data required by the CPU 75 to execute the programs.

The CPU 75 controls various sections of the digital camera 1 based onsignals from the various processing sections such as the manipulationsection 11 and the AF processing section 62.

The face detection processing section 80 detects a human face from alive view, a pre-image, or an actual image. Specifically, what isdetected as an face area includes, but is not limited to, an area havingfacial characteristics included in a face (for example, having skincolor, having eyes, having the shape of a face, or the like).

FIG. 2 is a flowchart of scene recognition main processing. Scenerecognition is to recognize that a subject at a time of photography isin a prescribed subject condition (photographic scene or simply scene).In other words, scene recognition is to recognize a type of aphotographic scene of frame image which a user desires to photograph. Aphotographic scene includes portrait, landscape, night scene, and macro(described later). Execution of the processing is controlled by the CPU75 of the digital camera 1. A program defining the processing is storedin the ROM 68. The processing is started when a photographic mode hasbeen set from the manipulation section 11 and, at the same time,“automatic scene recognition ON” has been set from the manipulationsection 11. The processing does not start when “automatic scenerecognition OFF” has been set from the manipulation section 11.

In S1, a determination is made on whether or not the processing is to beexecuted for the first time. If “Yes”, the main processing proceeds toS2. If “No”, the main processing proceeds to S3.

In S2, frame change reference information in the RAM 69 is initialized.The frame change reference information is information being referencedwhen a frame change check processing is performed. The frame changereference information is generated on the basis of photographicinformation which is information on photographic scene (information onframe image, described later), and updated on the basis of a total scenerecognition result in S13. The frame change reference informationincludes: a divisional photometric value; a focusing lens position; anin-focus AF area type (whether or not an AF area having entered afocused state is a face area detected by the face detection processingsection 80 or a default area in the vicinity of the center of a screen);an in-focus AF filter (for example, the low-pass filter and thehigh-pass filter according to Japanese Patent Application Laid-Open No.2006-145964); and the occurrence/nonoccurrence of face detection (facedetection result) by the face detection processing section 80. Inaddition, “status” in the RAM 69 is set to a search state, a checkcounter is set to 0, and a scene recognition history record retainingflag (flag indicating whether a scene recognition history record isretained) is set to OFF.

In S3, a determination is made on whether or not “status” in the RAM 69is a finalized state. If “Yes”, the main processing proceeds to S4. If“No”, the main processing proceeds to S7.

In S4, a frame change check is performed. This processing will bedescribed later.

In S5, as a result of the frame change check, a determination is made onwhether or not a frame change has occurred. If “Yes”, the mainprocessing proceeds to S6. If “No”, the main processing returns to S1.

In S6, it is determined that a scene change has occurred, whereby“status” in the RAM 69 is set to a search state.

In S7, a determination is made on whether or not the scene recognitionhistory record retaining flag in the RAM 69 is set to ON. If “Yes”, themain processing proceeds to S9. If “No”, the main processing proceeds toS8.

In S8, a scene recognition counter in the RAM 69 is set to 0. Inaddition, the scene recognition history records in the RAM 69 arecleared.

In S9, a single scene recognition operation by a recognizing section isperformed. This processing will be described later. As a result of thisprocessing, a single scene recognition result SR is stored in the RAM69. The single scene recognition result SR includes landscape, AUTO,portrait, night scene, macro, and the like. Details of processing forsingle scene recognition will be described later.

In S10, the scene recognition counter in the RAM 69 is incremented by 1.

In S11, the scene recognition counter in the RAM 69 and a predeterminedthreshold of the number of single scene recognition results(E_AUTOSR_SR_HISTORY_BEFORE_S1) of the ROM 68 are compared to determinewhether or not scene recognition counter threshold of the number ofsingle scene recognition results is true. If “Yes”, the main processingproceeds to S12. If “No”, the main processing proceeds to S17.

In S12, the scene recognition history record in the RAM 69 is checked. Ascene recognition history record includes a plurality of single scenerecognition results SR respectively individually stored by repeating S9until “status” reaches a finalized state.

In S13, total scene recognition is performed. That is, the scenerecognition result SR in the RAM 69 is updated to a scene recognitionresult SR having the greatest frequency of appearance in the scenerecognition history record including the plurality of scene recognitionresults SR stored at different times in S9. In addition, the framechange reference information of RAM 69 is updated to frame changereference information acquired at the same time point as the scenerecognition result SR having the greatest frequency of appearance.

In S14, a determination is made on whether or not the scene recognitionresult SR in the RAM 69 is different from “AUTO”. If “Yes”, the mainprocessing proceeds to S16. If “No”, the main processing proceeds toS15.

In S15, “status” in the RAM 69 is set to the search state and the mainprocessing returns to S1.

In S16, “status” in the RAM 69 is set to the finalized state and themain processing returns to S1.

FIG. 3 is a flowchart showing a detailed processing flow of the framechange check (S4). Execution of the processing is controlled by the CPU75 of the digital camera 1. A program defining the processing is storedin the ROM 68.

In S21, parameters “change” and “change_measure” in the RAM 69 are setto OFF and 0, respectively.

In S22, frame change reference information is generated based onphotographic information. The photographic information includes: a facedetection result; a focusing lens position; a zoom lens position; anin-focus state and a photometric value. Data items included in the framechange reference information can be the same as those included in thephotographic information. In addition, based on the generated framechange reference information, a first frame change check is performed.Here, the frame change check refers to a processing for detectingwhether a state (condition) of current frame is changed compared to astate of frame when previous scene recognition has been performed. Whena frame change is detected, it is judged that a photographic scene hasbeen changed and scene recognition is performed. In this case, while theframe change check is assumed to be any one of a photometric valuechange check, a focus position change check, and a face presence/absencechange check, other types may be included instead. These processing willbe described later. The result of the first frame change check is to bestored as E_AUTOSP_FRAME_CHECK1 that is a parameter in the RAM 69.

In S23, based on the result of the first frame change check in S22, adetermination is made on whether or not a frame change has occurred. If“Yes”, the processing proceeds to S24. If “No”, the processing proceedsto S26.

In S24, “change_measure” in the RAM 69 is incremented by 1.

In S25, “change_measure” in the RAM 69 and a predetermined thresholdE_AUTOSP_FRAME_CHANGE_MEASURE of the ROM 68 are compared to determinewhether or not “change_measure”≧E_AUTOSP_FRAME_CHANGE_MEASURE is true.If “No”, the processing proceeds to S26. If “Yes”, the processingproceeds to S35.

In S26, a second frame change check is performed. In this case, theframe change check is assumed to be any one selected from a photometricvalue change check, a focus position change check, and a facepresence/absence change check, but other than one selected in the firstframe change check. The result of the second frame change check is to bestored as E_AUTOSP_FRAME_CHECK2 that is a parameter in the RAM 69.

In S27, based on the result of the second frame change check in S26, adetermination is made on whether or not a frame change has occurred. If“Yes”, the processing proceeds to S28. If “No”, the processing proceedsto S30.

In S28, “change_measure” in the RAM 69 is incremented by 1.

In S29, “change_measure” in the RAM 69 and a thresholdE_AUTOSP_FRAME_CHANGE_MEASURE stored in the ROM 68 are compared todetermine whether or not “change_measure”≧E_AUTOSP_FRAME_CHANGE_MEASUREis true. If “No”, the processing proceeds to S30. If “Yes”, theprocessing proceeds to S35.

In S30, a third frame change check is performed. In this case, the framechange check is assumed to be any one selected from a photometric valuechange check, a focus position change check, and a face presence/absencechange check, but other than those selected in the first and secondframe change checks. The result of the third frame change check is to bestored as E_AUTOSP_FRAME_CHECK3 that is a parameter in the RAM 69.

In S31, based on the result of the third frame change check in S30, adetermination is made on whether or not a frame change has occurred. If“Yes”, the processing proceeds to S32. If “No”, the processing proceedsto S34.

In S32, “change_measure” in the RAM 69 is incremented by 1.

In S33, “change_measure” in the RAM 69 and a thresholdE_AUTOSP_FRAME_CHANGE_MEASURE stored in the ROM 68 are compared todetermine whether or not “change_measure”≧E_AUTOSP_FRAME_CHANGE_MEASUREis true. If “No”, the processing proceeds to S34. If “Yes”, theprocessing proceeds to S35.

In S34, it is determined that a frame change has not occurred. A flagindicating this determination may be stored in the RAM 69. Theprocessing then returns to S5 of the scene recognition main processing.

In S35, it is determined that a frame change has occurred. A flag“change” which is a flag indicating “frame change occurred” is set to ONand stored in the RAM 69. The processing then returns to S5 of the scenerecognition main processing.

FIG. 4 is a flowchart of a photometric value change check. Execution ofthe processing is controlled by the CPU 75 of the digital camera 1. Aprogram defining the processing is stored in the ROM 68.

In S41, a parameter “change_ev” in the RAM 69 is set to OFF. Inaddition, a parameter ev[i] in the RAM 69 is set to a photometric valueobtained from the photometry section 46 for the current frame image.Reference character “i” designates a suffix corresponding to each of Nnumber of blocks (N blocks) obtained by dividing the image intopredetermined units. In this case, it is assumed that i=0 to N−1.

In addition, a parameter “ev_base[i]” in the RAM 69 is set to adivisional photometric value of the frame change reference informationand the value is retained in the RAM 69. Moreover, “ev_base[i]” isinitialized in S2 and updated in S13 of the main processing. Inaddition, a weight w[i] corresponding to each block is read from the ROM68.

In S42, a parameter “delta_ev” is set in the RAM 69 according to thefollowing equation. Summation is to be performed for i=0 to N−1. Or,“delta_ev” may be a difference between brightnesses of the entirescreen.

delta_ev=ΣW[i]*|ev[i]−ev_base[i]|/ΣW[i]

The reason why summation is performed on absolute values of thedifferences of the respective areas is as follows. Absolute values aretaken in order to prevent summation from cancelling out changes in therespective areas and eliminating change as a whole even when significantchanges are actually occurring in the respective areas.

In S43, “delta_ev” in the RAM 69 and a threshold E_AUTOSP_FRAME_DELTA_EVstored in the ROM 68 is compared to determine whether or not“delta_ev”≧E_AUTOSP_FRAME_DELTA_EV is true. If “Yes”, the processingproceeds to S44. If “No”, the processing proceeds to S45.

In S44, it is determined that a change in the photometric value hasoccurred. A flag “change_ev” indicating that a change in the photometricvalue has occurred is set to ON and stored in the RAM 69.

In S45, it is determined that a change in the photometric value has notoccurred. A flag indicating that a change in the photometric value hasnot occurred may be stored in the RAM 69.

FIG. 5 is a flowchart of a focus position change check. Execution of theprocessing is controlled by the CPU 75 of the digital camera 1. Aprogram defining the processing is stored in the ROM 68.

In S51, a parameter “change_focal_point” in the RAM 69 is set to OFF, aparameter “focal_point” in the RAM 69 is set to a focusing lens position(number of drive pulses) set by the lens driving section 51 whenacquiring the current frame image, and a parameter “focal_point_base” inthe RAM 69 is set to the focusing lens position (that is initialized inS2 or updated in S13) of the frame change reference information, wherebya storage area for them is secured in the RAM 69.

In S52, “delta focal_point” is set to the RAM 69 according to thefollowing equation.

delta_focal_point=|focal_point−focal_point_base|

In S53, “delta_focal_point” in the RAM 69 and a predetermined focusposition change threshold stored in the ROM 68 are compared to determinewhether or not “delta_focal_point”>focus position change threshold istrue. If “Yes”, the processing proceeds to S54. If “No”, the processingproceeds to S55.

In S54, it is determined that a change in focus position has occurred.Subsequently, a flag “change_focal_point” indicating that a change infocus position has occurred is set to ON and stored in the RAM 69.

In S55, it is determined that a change in focus position has notoccurred. A flag indicating that a change in focus position has notoccurred may be stored in the RAM 69.

FIG. 6 is a flowchart of a face presence/absence change check. Executionof the processing is controlled by the CPU 75 of the digital camera 1. Aprogram defining the processing is stored in the ROM 68.

In S61, a parameter “change_face_result” in the RAM 69 is set to OFF.

In S62, a determination is made on whether or not theoccurrence/nonoccurrence of face detection outputted by the facedetection processing section 80 when the current frame image had beenacquired is consistent with the occurrence/nonoccurrence (that isinitialized in S2 or updated in S13) of face detection of the framechange reference information. If “Yes”, the processing proceeds to S64.If “No”, the processing proceeds to S63.

In S63, it is determined that a change in the occurrence/nonoccurrenceof face detection has occurred. A flag “change_face_result” indicatingthat a change in the occurrence/nonoccurrence of face detection hasoccurred is set to ON and stored in the RAM 69.

In S64, it is determined that a change in the occurrence/nonoccurrenceof face detection has not occurred. A flag indicating that a change inthe occurrence/nonoccurrence of face detection has not occurred may bestored in the RAM 69.

FIG. 7 is a flowchart showing details of a single scene recognitionoperation (S9) of the recognizing section. Execution of the processingis controlled by the CPU 75 of the digital camera 1. A program definingthe processing is stored in the ROM 68.

In S71, a determination is made on whether or not a flag(E_AUTOSR_SEARCH_TYPE) for carrying out a scene-dependent search andwhich is stored in the RAM 69 is set to 0. If “Yes”, the operationproceeds to S80. If “No”, the operation proceeds to S72. The value ofE_AUTOSR_SEARCH_TYPE is assumed to be arbitrarily settable from themanipulation section 11.

In S72, AUTO is set to the scene recognition result SR in the RAM 69.

In S73, E_AUTOSR_MODULE1 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. E_AUTOSR_MODULE1 is any integer from 0to 4. Subsequently, a scene judgment (recognition) subroutinecorresponding to module[i] is carried out. module[0] performs nothing.module[1] performs a portrait judgment to be described later. module[2]performs a landscape judgment to be described later. module[3] performsa night scene judgment to be described later. module[4] performs a macrojudgment to be described later.

In S74, based on the result of carrying out module[i] in S73, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S75. If “No”,the operation returns to S10 of the main processing.

In S75, E_AUTOSR_MODULE2 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. E_AUTOSR_MODULE2 is any integer from 0to 4 which is different from E_AUTOSR_MODULE1. Subsequently, a scenejudgment subroutine corresponding to module[i] is carried out.

In S76, based on the result of carrying out module[i] in S75, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S77. If “No”,the operation returns to S10 of the main processing.

In S77, E_AUTOSR_MODULE3 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. E_AUTOSR_MODULE3 is any integer from 0to 4 which is different from both E_AUTOSR_MODULE1 and E_AUTOSR_MODULE2.Subsequently, a scene judgment subroutine corresponding to module[i] iscarried out.

In S78, based on the result of carrying out module[i] in S77, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S79. If “No”,the operation returns to S10 of the main processing.

In S79, E_AUTOSR_MODULE4 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. E_AUTOSR_MODULE3 is any integer from 0to 4 which is different from E_AUTOSR_MODULE1, E_AUTOSR_MODULE2, andE_AUTOSR_MODULE3. Subsequently, a scene judgment subroutinecorresponding to module[i] is carried out. Values of E_AUTOSR_MODULE1,E_AUTOSR_MODULE2, E_AUTOSR_MODULE3, and E_AUTOSR_MODULE4 may be set inany way. However, it is preferable that a smaller number is assigned toa type of a scene judgment which needs to be preferentially performed.For example, when it is desirable to perform scene judgment in an orderof portrait judgment>landscape judgment>night scene judgment>macrojudgment, then E_AUTOSR_MODULE1=1, E_AUTOSR_MODULE2=2,E_AUTOSR_MODULE3=3, and E_AUTOSR_MODULE4=4 shall suffice. These valuesmay alternatively be arranged so as to be arbitrarily settable from themanipulation section 11.

In S80, a determination is made on whether or not the current scenerecognition result SR in the RAM 69 is AUTO. If “Yes”, the operationproceeds to S72. If “No”, the operation proceeds to S81.

In S81, the current scene recognition result SR in the RAM 69 is set toa parameter “SR_old” in the RAM 69. In other words, if the current scenerecognition result SR in the RAM 69 is AUTO then “SR_old”=0, if thecurrent scene recognition result SR in the RAM 69 is portrait then“SR_old”=1, if the current scene recognition result SR in the RAM 69 islandscape then “SR_old”=2, if the current scene recognition result SR inthe RAM 69 is night scene then SR_old=3, and if the current scenerecognition result SR in the RAM 69 is macro then “SR_old”=4.

In S82, “SR_old” is substituted into the parameter i in the RAM 69.Subsequently, a scene judgment subroutine corresponding to module[i] iscarried out.

In S83, based on the result of carrying out module[i] in S82, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S84. If “No”,the operation returns to S10 of the main processing.

In S84, a determination is made on whether or not“SR_old”=E_AUTOSR_MODULE1. If “Yes”, the operation proceeds to S87. If“No”, the operation proceeds to S85.

In S85, E_AUTOSR_MODULE1 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. Subsequently, a scene judgmentsubroutine corresponding to module[i] is carried out.

In S86, based on the result of carrying out module[i] in S85, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S87. If “No”,the operation returns to S10 of the main processing.

In S87, a determination is made on whether or not“SR_old”=E_AUTOSR_MODULE2. If “Yes”, the operation proceeds to S90. If“No”, the operation proceeds to S88.

In S88, E_AUTOSR_MODULE2 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. Subsequently, a scene judgmentsubroutine corresponding to module[i] is carried out.

In S89, based on the result of carrying out module[i] in S88, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S90. If “No”,the operation returns to S10 of the main processing.

In S90, a determination is made on whether or not“SR_old”=E_AUTOSR_MODULE3. If “Yes”, the operation proceeds to S93. If“No”, the operation proceeds to S91.

In S91, E_AUTOSR_MODULE3 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. Subsequently, a scene judgmentsubroutine corresponding to module[i] is carried out.

In S92, based on the result of carrying out module[i] in S91, adetermination is made on whether or not the scene recognition result SRin the RAM 69 is AUTO. If “Yes”, the operation proceeds to S93. If “No”,the operation returns to S10 of the main processing.

In S93, a determination is made on whether or not“SR_old”=E_AUTOSR_MODULE4. If “Yes”, the processing returns to S10 ofthe main processing. If “No”, the operation proceeds to S94.

In S94, E_AUTOSR_MODULE4 stored in advance in the ROM 68 is substitutedinto parameter i in the RAM 69. Subsequently, a scene judgmentsubroutine corresponding to module[i] is carried out. The processingthen returns to S10 of the main processing.

FIG. 8 is a flowchart showing details of a scene judgment subroutine(portrait judgment, module[1]). Execution of the processing iscontrolled by the CPU 75 of the digital camera 1. A program defining theprocessing is stored in the ROM 68.

In S101, a determination is made on whether or not the face detectionprocessing section 80 has detected a face. If “Yes”, the subroutineproceeds to S102. If “No”, the subroutine proceeds to S105.

In S102, a determination is made on whether or not a face limitationflag in the RAM 69 is turned on. If “Yes”, the subroutine proceeds toS103. If “No”, the subroutine proceeds to S104.

In S103, with respect to a face area set in an AF evaluation valuecalculation area, a determination is made on: whether or not the size ofthe face is within a predetermined range; the tilt of the face is withina predetermined range; the orientation of the face is within apredetermined range; the accuracy score of the face is within apredetermined range; and the position of the face is within apredetermined range. If “No”, the subroutine proceeds to S103. If “Yes”,the subroutine proceeds to S104.

In S104, the scene recognition result SR is set to portrait.Subsequently, the subroutine proceeds to processing subsequent tomodule[1] or, in other words, any one of processing subsequent to S73,S75, S77, and S79 or any one of processing subsequent to S85, S88, S91,and S94.

In S105, the scene recognition result SR is set to AUTO.

FIG. 9 is a flowchart showing details of a scene judgment subroutine(landscape judgment, module[2]). Execution of the processing iscontrolled by the CPU 75 of the digital camera 1. A program defining theprocessing is stored in the ROM 68.

In S111, a determination is made on whether or not half-press (S1) ofthe shutter button has been locked. If “Yes”, the subroutine proceeds toS124. If “No”, the subroutine proceeds to S112.

In S112, a determination is made on whether or not the execution ofcontinuous AF (hereinafter denoted to as “CAF”) has been set in advancevia settings menu or the manipulation section 11. If “Yes”, thesubroutine proceeds to S113. If “No”, the subroutine proceeds to S129.

In S113, a determination is made on whether or not the AF evaluationvalue calculated by the pre-actual photography AF processing section 81is higher than a predetermined threshold stored in the ROM 68. If “Yes”,the subroutine proceeds to S114. If “No”, the subroutine proceeds toS119. Moreover, the present step S113 may be omitted. In this case, thesubroutine proceeds to S114 if “Yes” in S112. In addition, the varioussubsequent processing (S119, S120, S121, S122, and S123) when “No” isdetermined in S113 is also omitted.

In S114, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH stored in the ROM 68 is 0. If “Yes”, thesubroutine proceeds to S115. If “No”, the subroutine proceeds to S116.

In S115, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the infinity (INF) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus subject is more distant than apredetermined distance. If “Yes”, the subroutine proceeds to S125. If“No”, the subroutine proceeds to S129.

In S116, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH=1 is true. If “Yes”, the subroutineproceeds to S117. If “No”, the subroutine proceeds to S118.

In S117, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF, anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S125. If “No”, thesubroutine proceeds to S129.

In S118, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S125. If “No”, thesubroutine proceeds to S129.

In S119, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW stored in the ROM 68 is 0. If “Yes”, thesubroutine proceeds to S120. If “No”, the subroutine proceeds to S121.

In S120, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the infinity (INF) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus position is more distant than apredetermined distance. If “Yes”, the subroutine proceeds to S125. If“No”, the subroutine proceeds to S129.

In S121, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW=1 is true. If “Yes”, the subroutineproceeds to S122. If “No”, the subroutine proceeds to S123.

In S122, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S125. If “No”, thesubroutine proceeds to S129.

In S123, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S125. If “No”, thesubroutine proceeds to S129.

In S124, a determination is made on whether or not an in-focus positionhas been determined by AF processing of the AF processing section 62 anda focal distance corresponding to the in-focus position is to theinfinity (INF) side of a predetermined focal distance threshold storedin the ROM 68 or, in other words, whether or not the focal distance isgreater than a predetermined distance. If “Yes”, the subroutine proceedsto S125. If “No”, the subroutine proceeds to S129.

In S125, a determination is made on whether or not the subject luminancemeasured by the control circuit 74 is lower than a predeterminedthreshold stored in the ROM 68. If “Yes”, the subroutine proceeds toS126. If “No”, the subroutine proceeds to S129.

In S126, a determination is made on whether or not a landscape zoominformation flag has been set to ON in advance as a set parameter of ROM68 or from the manipulation section 11. If “Yes”, the subroutineproceeds to S126. If “No”, the subroutine proceeds to S129.

In S127, a determination is made on whether or not the zoom lensposition is within a predetermined range, such as on the wide side of apredetermined position. If “Yes”, the subroutine proceeds to S128. If“No”, the subroutine proceeds to S129. Note that the zoom position notbeing within a predetermined range refers to a case where, for example,the zoom lens position is at the tele end or the vicinity thereof. Inthis case, since a panoramic view cannot be fit into the field angle andis therefore unsuited for landscape photography, the photographic sceneis determined to be AUTO.

In S128, SR is set to landscape. The subroutine then proceeds toprocessing subsequent to module[2].

In S129, SR is set to AUTO. The subroutine then proceeds to processingsubsequent to module[2].

FIG. 10 is a flowchart showing details of a scene judgment subroutine(night scene judgment, module[3]). Execution of the processing iscontrolled by the CPU 75 of the digital camera 1. A program defining theprocessing is stored in the ROM 68.

In S131, a determination is made on whether or not the subject luminancemeasured by the control circuit 74 is lower than a predeterminedthreshold stored in the ROM 68. If “Yes”, the subroutine proceeds toS132. If “No”, the subroutine proceeds to S152.

In S132, a determination is made on whether or not half-press (S1) ofthe shutter button has been locked. If “Yes”, the subroutine proceeds toS147. If “No”, the subroutine proceeds to S133.

In S133, a determination is made on whether or not a night scenejudgment flag prior to half-press (S1) stored in the RAM 69 has been setto ON. If “Yes”, the subroutine proceeds to S134. If “No”, the mainsubroutine proceeds to S152.

In S134, a determination is made on whether or not distance informationhas been set to be used in night scene judgment by an input from themanipulation section 11 or a parameter stored in the ROM 68. If distanceinformation has been set to be used in night scene judgment, thesubroutine proceeds to S135. If distance information has not been set tobe used in night scene judgment, the subroutine proceeds to S149.

In S135, a determination is made on whether or not the execution of CAFhas been set in advance via settings menu or the manipulation section11. If “Yes”, the subroutine proceeds to S136. If “No”, the mainsubroutine proceeds to S152.

In S136, a determination is made on whether or not the AF evaluationvalue calculated by the pre-actual photography AF processing section 81is higher than a predetermined threshold stored in the ROM 68. If “Yes”,the subroutine proceeds to S137. If “No”, the subroutine proceeds toS142. Moreover, the present step S136 may be omitted. In this case, thesubroutine proceeds to S137 if “Yes” in S135. In addition, the varioussubsequent processing when “No” is determined in S136 is also omitted.

In S137, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH=0 is true. If “Yes”, the subroutineproceeds to S138. If “No”, the subroutine proceeds to S139.

In S138, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the infinity (INF) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus position is more distant than apredetermined distance. If “Yes”, the subroutine proceeds to S149. If“No”, the subroutine proceeds to S152.

In S139, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH=1 is true. If “Yes”, the subroutineproceeds to S140. If “No”, the subroutine proceeds to S141.

In S140, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S149. If “No”, thesubroutine proceeds to S152.

In S141, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S149. If “No”, thesubroutine proceeds to S152.

In S142, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW=0 is true. If “Yes”, the subroutineproceeds to S143. If “No”, the subroutine proceeds to S144.

In S143, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the infinity (INF) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus position is more distant than apredetermined distance. If “Yes”, the subroutine proceeds to S149. If“No”, the subroutine proceeds to S152.

In S144, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW=1 is true. If “Yes”, the subroutineproceeds to S145. If “No”, the subroutine proceeds to S146.

In S145, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S149. If “No”, thesubroutine proceeds to S152.

In S146, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the infinity (INF) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is greater than a predetermineddistance. If “Yes”, the subroutine proceeds to S149. If “No”, thesubroutine proceeds to S152.

In S147, a determination is made on whether or not distance informationhas been set to be used in night scene judgment by an input from themanipulation section 11 or a parameter stored in the ROM 68. If distanceinformation has been set to be used in night scene judgment, thesubroutine proceeds to S148. If distance information has not been set tobe used in night scene judgment, the subroutine proceeds to S149.

In S148, a determination is made on whether or not an in-focus positionhas been determined by AF processing of the AF processing section 62 anda focal distance corresponding to the in-focus position is to theinfinity (INF) side of a predetermined focal distance threshold storedin the ROM 68 or, in other words, whether or not the focal distance isgreater than a predetermined distance. If “Yes”, the subroutine proceedsto S149. If “No”, the subroutine proceeds to S152.

In S149, a determination is made on whether or not a night scene zoominformation flag has been set to ON in advance as a set parameter of ROM68 or from the manipulation section 11. If “Yes”, the subroutineproceeds to S150. If “No”, the subroutine proceeds to S151.

In S150, a determination is made on whether or not the zoom lensposition is within a predetermined range, such as on the wide side of apredetermined position. If “Yes”, the subroutine proceeds to S151. If“No”, the subroutine proceeds to S152. Note that the zoom position notbeing within a predetermined range refers to a case where, for example,the zoom lens position is at the tele end or the vicinity thereof. Inthis case, since a background distant landscape with low incident lightintensity cannot be fit into the field angle and is therefore unsuitedfor night scene photography, the photographic scene is determined to beAUTO.

In S151, SR is set to night scene. The subroutine then proceeds toprocessing subsequent to module[3].

In S152, SR is set to AUTO. The subroutine then proceeds to processingsubsequent to module[3].

FIG. 11 is a flowchart showing another example of a scene judgmentsubroutine (night scene judgment, module[3]). Execution of theprocessing is controlled by the CPU 75 of the digital camera 1. Aprogram defining the processing is stored in the ROM 68. For night scenejudgment, adopting either FIG. 10 or 11 shall suffice. Alternatively, anarrangement is also possible in which either one is selectivelyexecuted.

In S161, a determination is made on whether or not the subject luminancemeasured by the control circuit 74 is lower than a predeterminedthreshold stored in the ROM 68. If “Yes”, the subroutine proceeds toS162. If “No”, the subroutine proceeds to S168. This threshold mayeither be the same as or different from the threshold for judgingwhether or not emission is to be instructed to the fill light controlsection 25.

In S162, a determination is made on whether or not half-press (S1) ofthe shutter button has been locked. If “Yes”, the subroutine proceeds toS163. If “No”, the subroutine proceeds to S168.

In S163, a determination is made on whether or not emission of the filllight 26 has been instructed to the fill light control section 25. If“Yes”, the subroutine proceeds to S164. If “No”, the subroutine proceedsto S168.

In S164, a determination is made on whether or not a difference betweensubject luminances respectively measured by the control circuit 74immediately before and immediately after the fill light control section25 causes the fill light emitting section 26 to be emitted exceeds apredetermined threshold stored in the ROM 68. If “Yes”, the subroutineproceeds to S168. If “No”, the subroutine proceeds to S165. Moreover, ifthe difference has not exceeded the threshold and is minute, it may bedescribed that the contribution of an increase in subject luminance dueto fill light irradiation is minimal and the subject is not near.

In S165, a determination is made on whether or not the night scene zoominformation flag has been set to ON in advance as a set parameter of ROM68 or from the manipulation section 11. If “Yes”, the subroutineproceeds to S166. If “No”, the subroutine proceeds to S167.

In S166, a determination is made on whether or not the zoom lensposition is within a predetermined range, such as on the wide side of apredetermined position. If “Yes”, the subroutine proceeds to S167. If“No”, the subroutine proceeds to S168. Note that the zoom position notbeing within a predetermined range refers to a case where, for example,the zoom lens position is at the tele end or the vicinity thereof. Inthis case, a background distant landscape cannot be fit into the fieldangle and is therefore unsuited for night scene photography.

In S167, SR is set to night scene. The subroutine then proceeds toprocessing subsequent to module[3].

In S168, SR is set to AUTO. The subroutine then proceeds to processingsubsequent to module[3].

FIG. 12 is a flowchart showing details of a scene judgment subroutine(macro judgment, module[4]). Execution of the processing is controlledby the CPU 75 of the digital camera 1. A program defining the processingis stored in the ROM 68.

In S171, a determination is made on whether or not half-press (S1) ofthe shutter button has been locked. If “Yes”, the subroutine proceeds toS184. If “No”, the subroutine proceeds to S172.

In S172, a determination is made on whether or not the execution of CAFhas been set in advance via settings menu or the manipulation section11. If “Yes”, the subroutine proceeds to S173. If “No”, the subroutineproceeds to S188.

In S173, a determination is made on whether or not the AF evaluationvalue calculated by the pre-actual photography AF processing section 81is higher than a predetermined threshold stored in the ROM 68. If “Yes”,the subroutine proceeds to S174. If “No”, the subroutine proceeds toS179. Moreover, the present step S173 may be omitted. In this case, thesubroutine proceeds to S174 if “Yes” in S172. In addition, the varioussubsequent processing is also omitted when “No” is determined in S173.

In S174, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH=0 is true. If “Yes”, the subroutineproceeds to S175. If “No”, the subroutine proceeds to S176.

In S175, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the near (NEAR) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus position is closer than apredetermined distance. If “Yes”, the subroutine proceeds to S185. If“No”, the subroutine proceeds to S188.

In S176, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_HIGH=1 is true. If “Yes”, the subroutineproceeds to S177. If “No”, the subroutine proceeds to S178.

In S177, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF, anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the near (NEAR) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is shorter than a predetermineddistance. If “Yes”, the subroutine proceeds to S185. If “No”, thesubroutine proceeds to S188.

In S178, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the near (NEAR) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is closer than a predetermineddistance. If “Yes”, the subroutine proceeds to S185. If “No”, thesubroutine proceeds to S188.

In S179, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW=0 is true. If “Yes”, the subroutineproceeds to S180. If “No”, the subroutine proceeds to S181.

In S180, a determination is made on whether or not an in-focus positiondecided as a result of the CAF is to the near (NEAR) side of apredetermined focal distance threshold stored in the ROM 68 or, in otherwords, whether or not the in-focus position is closer than apredetermined distance. If “Yes”, the subroutine proceeds to S185. If“No”, the subroutine proceeds to S188.

In S181, a determination is made on whether or notE_AUTOSR_CHECK_CAFSTATUS_LOW=1 is true. If “Yes”, the subroutineproceeds to S182. If “No”, the subroutine proceeds to S183.

In S182, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF, anda focal distance corresponding to the in-focus position determined bythe local maximum point is to the near (NEAR) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is shorter than a predetermineddistance. If “Yes”, the subroutine proceeds to S185. If “No”, thesubroutine proceeds to S188.

In S183, a determination is made on whether or not a local maximum pointof the AF evaluation value has been detected as a result of the CAF orthe AF evaluation value is in the vicinity of the local maximum point(such as a case where the subroutine is in the stage of “fineadjustment” described in paragraph 0041 of Japanese Patent ApplicationLaid-Open No. 2003-348426 by the present applicant), and whether or nota focal distance corresponding to the in-focus position determined bythe local maximum point is to the near (NEAR) side of a predeterminedfocal distance threshold stored in the ROM 68 or, in other words,whether or not the focal distance is closer than a predetermineddistance. If “Yes”, the subroutine proceeds to S185. If “No”, thesubroutine proceeds to S188.

In S184, a determination is made on whether or not an in-focus positionhas been determined by AF processing of the AF processing section 62 anda focal distance corresponding to the in-focus position is to the near(NEAR) side of a predetermined focal distance threshold stored in theROM 68 or, in other words, whether or not the focal distance is closerthan a predetermined distance. If “Yes”, the subroutine proceeds toS185. If “No”, the subroutine proceeds to S188.

In S185, a determination is made on whether or not a macro zoominformation flag has been set to ON in advance as a set parameter of ROM68 or from the manipulation section 11. If “Yes”, the subroutineproceeds to S186. If “No”, the subroutine proceeds to S187.

In S186, a determination is made on whether or not the zoom lensposition is within a predetermined range stored in the ROM 68, such ason the wide side of a predetermined position. If “Yes”, the subroutineproceeds to S187. If “No”, the subroutine proceeds to S188. Note thatthe zoom position not being within a predetermined range refers to acase where, for example, the zoom lens position is at anywhere otherthan the wide end or the vicinity thereof. In this case, focusing of theproximal subject cannot be achieved and is therefore unsuited for closephotography.

In S187, SR is set to macro. The subroutine then proceeds to processingsubsequent to module[4].

In S188, SR is set to AUTO. The subroutine then proceeds to processingsubsequent to module[4].

FIG. 13 is a flowchart showing scene recognition processing according tothe first embodiment of the present invention. The flowchart in FIG. 13explains the single scene recognition and the total scene recognition inS9 to S13 in FIG. 2, in more detail.

First, photographic information including a face detection result, afocusing lens position, a zoom lens position, an in-focus state and aphotometric value is acquired by the CPU 75, and scene recognition(above-described single scene recognition) is performed using theinformation (step ST10).

Storage areas of scene recognition history record on the memory (RAM 69)are shifted to create a free area for storing the newest value of thesingle scene recognition result (step ST12). The newest scenerecognition result in step S10 is written into the storage area for thenewest value (step ST14). ST10 to ST14 are repeated until the scenerecognition counter becomes a predetermined number (a threshold of thenumber of single scene recognition results) or more.

Further, the digital camera 1 (CPU 75) judges a current scene SR basedon the history record of single scene recognition results (scenerecognition history record) recorded in the RAM 69 and sets aphotographing mode suitable for photographing each scene. Hereinafter,scene judgment (recognition) based on scene recognition history recordshall be referred to as total scene recognition.

In the total scene recognition, scene recognition history record is read(step ST16), and based on the scene recognition history record, thecurrent scene SR is judged (step ST18). A photographing mode is set inaccordance with the judgment result of the scene SR. In step ST18, forexample, the scene SR currently being photographed is judged based onthe number of recognitions (recognition frequency) and the newness ofthe recognition result in the scene recognition history record.

The digital camera 1 according to the present embodiment, in the totalscene recognition, judges a scene SR currently being photographed basedon the number of recognitions (recognition frequency) and the newness ofrecognition results with in the scene recognition history record. FIGS.14 and 15 are diagrams schematically showing total scene recognitionprocessing in S13.

As shown in State A in State A in FIG. 14, storage areas A[0], A[1],A[2], . . . for sequentially storing single scene recognition resultsare provided on the RAM 69 of the digital camera 1. In the example shownin State A in FIG. 14, each scene is represented by a predeterminednumeral (hereinafter referred to as scene ID). “0” when the scene is“AUTO”, “1” when the scene is “portrait”, “2” when the scene is“landscape”, “3” when the scene is “night scene”, and “4” when the sceneis “macro” are to be written, as scene IDs, in a storage area A[i](where i=0, 1, 2, . . . ) in the RAM 69. The single scene recognitionresult in storage area A[0] is the newest, and single scene recognitionresults become older in the order of A[1], A[2], . . . .

As shown in State A in FIG. 14, five scene recognition results SR aresuccessively stored from the oldest to the newest. A suffix j=0 to 4 isattached to each scene recognition result SR, where the smaller thenumber, the more recent the scene recognition result. A case where thenumber of accumulated scene recognition results is 5 is merely anexample and any integer equal to or greater than 3 shall suffice.

Each time module[i], which is single scene recognition, is executed inS73, S75, S77, and S79 or in S85, S88, S91, and S94, a new scenerecognition result SR is acquired. As a result, the suffixes of previousscene recognition results SR accumulated up to then are incremented by 1and the previous scene recognition results SR become those onegeneration older. The new scene recognition result SR is attached with asuffix of 0 to become a current scene recognition result.

In other words, as shown in State B in FIG. 14, when single scenerecognition is executed, storage areas A[0], A[1], A[2], . . . for thescene recognition history record on the RAM 69 shift such thatA[0]→A[1], A[1]→A[2], A[2]→A[3], . . . , whereby the storage area A[0]of the newest single scene recognition result becomes a free area.Subsequently, as shown in State C in FIG. 14, the newest single scenerecognition result is written into the free area A[0].

In State B in FIG. 14, what was SR[0]=3, SR[1]=3, SR[2]=3, SR[3]=0 andSR[4]=1 in State A in FIG. 14 becomes SR[1]=3, SR[2]=3, SR[3]=3, andSR[4]=0 as a result of the addition of a new single scene recognitionresult SR[0]=2. Prior to the addition of the new single scenerecognition result SR[0], the single scene recognition result of theoldest generation SR[4]=1 may either be deleted from or stored in theRAM 69 upon the addition of the new single scene recognition result.

In S13, when a new single scene recognition result is added, a singlescene recognition result with the highest frequency of appearance amongSR[0], SR[1], SR[2], SR[3], and SR[4] is identified and re-assumed to bethe scene recognition result SR (total scene recognition result).

In the example shown in State C in FIG. 14, “night scene” represented by“3” and which appears three times in the scene recognition historyrecord has the greatest frequency. The CPU 75 sets the total scenerecognition result to SR=3 and sets the photographing mode to the nightscene mode. Consequently, photographing and recording of images can beexecuted under photographic conditions and image processing conditionsof the night scene mode. Further, the frame change reference informationis updated based on photographic information used at the point ofobtaining the newest one among the single scene recognition results withthe greatest frequency. In State C in FIG. 14, the single scenerecognition results of the greatest frequency, i.e., 3, are SR[1], SR[2]and SR[3]. Among them, the newest single scene recognition result isSR[1], and thus, the frame change reference information is updated basedon photographic information used at the point of obtaining the singlescene recognition result SR[3].

When there are a plurality of single scene recognition results whichshare the greatest frequency of appearance, the single scene recognitionresult of the newest generation is assumed to be the scene recognitionresult SR. For example, in State C in FIG. 15, SR[0]=1, SR[1]=2,SR[2]=3, SR[3]=3 and SR[4]=2. In this case, because SR[1]=SR[4]=2, andSR[2]=SR[3]=3, “landscape” represented by “2” and “night scene”represented by “3” respectively appear twice (has maximum frequency) inthe scene recognition history record. In this case, total scenerecognition is performed based on the newness of the single scenerecognition results. In the example shown in State C in FIG. 15, sincethe single scene recognition result SR[1] having the value of “2” isstored in a storage area on the newer side than the single scenerecognition results having the value of “3”, the CPU 75 sets the totalscene recognition result to SR=2 and sets the photographing mode to thelandscape mode. Further, the CPU 75 updates the frame change referenceinformation based on photographic information used at the point ofobtaining the single scene recognition result SR[1].

Results of the scene judgments shown in FIGS. 8 to 15 are controlled bya CPU 75 so as to be displayed on the display section 71.

For example, as shown in FIG. 16, characters such as “landscape”,“AUTO”, “portrait”, “night scene”, “macro”, and the like which areresults of scene judgments are superimposed on a live view or arecording image subsequent to the shutter button being fully pressed,and displayed on the display section 71. Character strings, icons,symbols, and other information indicating scene judgment results aregenerated by an OSD circuit, not shown. If the camera 1 is provided withan sound processing circuit or a speaker, the sound processing circuitor the speaker may be controlled by the CPU 75 so as to output an alarmsound corresponding to the scene judgment result. The scene judgmentresult is not displayed if “automatic scene recognition OFF” has beenset.

From the processing described above, it is possible for a user torecognize what kind of scene the user is attempting to photograph or hasalready photographed. As shown in FIG. 16, the recognition result isnotified in a form readily understandable by the user as a text or anicon display. Recognizable scenes are: portrait (FIG. 8), landscape(FIG. 9), night scene (FIGS. 10 and 11), and macro (FIG. 12). AUTO isset when the scene judgment result does not fit any of these scenes.

In the main processing shown in FIG. 2, scene recognition is performedwhen a scene change is detected. A frame status when the previous scenerecognition result is finalized and changes in the state of a currentframe are monitored (S4, FIG. 3). If it is determined that a scenechange has occurred when a change has occurred (S5), “status” enters asearch state (S6), and the recognizing section becomes operational atthe timing of the scene change (S9).

In the frame change check shown in FIG. 3, a plurality of factors fordetecting change can be retained, and the order the factors can beshuffled through the settings of E_AUTOSR_FRAME_CHECK1 to 3. When achange is detected, the value of “change_measure” which is an indicatorof frame change is incremented (S24, S28, S32). When the value of“change_measure” is equal to or greater thanE_AUTOSR_FRAME_CHANGE_MEASURE (“Yes” in S25, S29, S33), it is determinedthat a frame change has occurred (S35).

Here, photometric value change check (FIG. 4), focus position changecheck (FIG. 5), and face presence/absence change check (FIG. 6) areshown as specific processing for detecting a frame change. Moreover,although not shown, a frame change may alternatively be detecteddepending on the occurrence/nonoccurrence of in-focus detection by thepre-actual photography AF processing section 81.

In the photometric value change check shown in FIG. 4, “delta_ev” whichacts as an indicator of change amount of a photometric value(photometric value change amount) is determined by calculating aphotometric value change amount for each of N segmented areas,performing weighting using weights corresponding to the respectiveareas, and taking a summation them. Furthermore, an occurrence of aphotometric value change is determined when the value of “delta_ev” isequal to or greater than E_AUTOSP_FRAME_DELTA_EV.

In the focus position change check in FIG. 5, “delta_focal_point” whichis an indicator of a focus position change amount is calculated based ona difference between the focus position in the frame change referenceinformation (reference information) and a current focus position. Anoccurrence of a photometric value change is determined when the value of“delta_focal_point” is equal to or greater than a focus position changethreshold. Moreover, the threshold used here is assumed having been setin ROM 68 for each zoom position.

In the face presence/absence change check in FIG. 6, it is determinedthat a face presence/absence change has occurred when the facepresence/absence result in the reference information and the currentface presence/absence result differ from each other.

Scene recognition history record used in operations of the recognizingsection is cleared after obtaining an SR (total scene recognitionresult) to be adopted as a result of automatic scene recognition (S8).This is performed to prevent information obtained at separated timepoints from being referenced in scene recognition because therecognizing section is not assumed to be always operational.

Here, in order to clear scene recognition history record, an arrangementis provided in which SR is not updated from the point where the “status”is set to a search state (S6) until the point where the recognizingsection operates as many times as needed to obtain a number of singlescene recognition results required in total scene recognition (until S11results in “Y”).

In addition, upon determining SR, the (newest) photographic informationat the point when the adopted SR with greatest frequency is stored asframe change reference information for checking frame changes (S13).

Moreover, the “status” is set to “finalized state” when the determinedSR is other than AUTO (S16), and the recognizing does not work until thescene changes. On the other hand, the “status” is set to “search state”when the determined SR is AUTO (S15), and the recognizing sectioncontinues its processing. This is because it is possible that a scenechange cannot be correctly detected if the “status” is set to “finalizedstate” based on a recognition result obtained in the middle of scenechange.

If, for example, when a state in the middle of a scene change isregistered as reference information, and then a frame change is checked,it is possible that the recognizing section cannot work due to the smalldifference from the reference information even though it is desired thatthe recognizing section become operational in a state where the scenechange is ultimately concluded. Therefore, in order to avoid thisproblem, processing is performed to update the reference informationbased on photographic information corresponding to the finalized sceneas described above (S13).

Unless the result of scene recognition can be stabilized, an outputresult will confuse the user. Therefore, by performing processing fordetermining what type of scene a particular scene is (S7 to S16) andprocessing for monitoring whether or not a change has occurred from arecognized scene (S4 to S6) in a mixed manner, it becomes now possibleto perform scene recognition in an accurate and stable manner.

Second Embodiment

FIG. 17 is a flowchart of a frame change check subroutine according to asecond embodiment. This processing can be executed in place of theprocessing shown in FIG. 3. Execution of the processing is controlled bythe CPU 75 of the digital camera 1. A program defining the processing isstored in the ROM 68.

S201 to S203 are the same as S21 to S23.

In S204, a value obtained by adding a weight E_AUTOSP_FRAME_CHECK1corresponding to the first frame change check to the parameter“change_measure” in the RAM 69 is set as the new “change_measure”.E_AUTOSP_FRAME_CHECK1 is stored in advance in the ROM 68.

S205 to S207 are the same as S25 to S27.

In S208, a value obtained by adding a weight E_AUTOSP_FRAME_CHECK2corresponding to the second frame change check to the parameter“change_measure” in the RAM 69 is set as the new “change_measure”.E_AUTOSP_FRAME_CHECK2 is stored in advance in the ROM 68.

S209 to S211 are the same as S29 to S31.

In S212, a value obtained by adding a weight E_AUTOSP_FRAME_CHECK3corresponding to the third frame change check to the parameter“change_measure” in the RAM 69 is set as the new “change_measure”.E_AUTOSP_FRAME_CHECK3 is stored in advance in the ROM 68.

S213 to S215 are the same as S33 to S35.

FIG. 18 is a table stored in the ROM 68 showing a relationship betweenan example of weights E_AUTOSP_FRAME_CHECK1 to 3 corresponding to thefirst to third frame change checks and an example of “change_measure”values corresponding to the occurrence/nonoccurrence of changesaccording to the first to third frame change checks.

In this case, as an example, it is assumed that: the first frame changecheck is face presence/absence change (FIG. 6); the second frame changecheck is focus position change (FIG. 5); the third frame change check isphotometric value change (FIG. 4); and that E_AUTOSP_FRAME_CHECK1=2,E_AUTOSP_FRAME_CHECK2=1, and E_AUTOSP_FRAME_CHECK3=1 are set. In otherwords, face presence/absence change is assigned a greater weight thanthose of focus position change and photometric value change.

Although the table covers all possible change result combinations of thefirst to third frame change checks, the depiction thereof is omitted.For example, in the case of E_AUTOSP_FRAME_CHANGE_MEASURE=2, if it isdetermined by the first frame change check (face presence/absencechange) that a change has occurred, thenchange_measure=2=E_AUTOSP_FRAME_CHANGE_MEASURE becomes true. Therefore,“Yes” is determined in S205, and the subroutine proceeds to S215 whereit is determined that a frame change has occurred. In other words, sincethe weight corresponding to face presence/absence change is large, theoccurrence of a face presence/absence change alone immediately resultsin an occurrence of a frame change.

On the other hand, when it is determined in the first frame change check(face presence/absence change) that a change has not occurred,change_measure=1<E_AUTOSP_FRAME_CHANGE_MEASURE becomes true even when itis determined in the second frame change check (focus position change)that a change has occurred. Therefore, unless it is determined in thethird frame change check that a change has occurred, then “No” isdetermined in S213, and the subroutine proceeds to S214 where it isdetermined that a frame change has not occurred. In other words, sincethe weight corresponding to (assigned to) the focus position change issmall, an occurrence of a focus position change alone does notimmediately result in an occurrence of a frame change, and an occurrenceof a frame change is determined only upon the occurrence of a change dueto additional another factor.

The contents of the table shown in FIG. 18 or, in other words, theweights corresponding to the respective frame change checks and thevalue of E_AUTOSP_FRAME_CHANGE_MEASURE can be freely set by the user viathe manipulation section 11 from an “important item selection” screendisplayed on the display section 71.

Accordingly, when there are a plurality of factors that determinewhether a scene has changed, scene change criteria can be expressed invarious forms by enabling weights corresponding to the respectivefactors to be settable. If the user is able to freely set conditions fordetermination of an occurrence of scene change, scene change criteriacan be customized and a change in a factor emphasized by the user can bestrongly reflected onto scene change determination.

Third Embodiment

FIG. 19 is a flowchart of main processing according to a thirdembodiment. This processing can be executed in place of the processingshown in FIG. 2. Execution of the processing is controlled by the CPU 75of the digital camera 1. A program defining the processing is stored inthe ROM 68. In this embodiment, frame change check (single frame changecheck) are performed based on frame change reference information andphotographic information a plurality of times, and further, the framechange check results are accumulated as frame change history record, andframe change check (total frame change check) is performed based on theframe change history record.

S301 to S303 are the same as S1 to S3. However, in S302, frame changehistory record is also initialized.

In S304, frame change history record stored in RAM 69 is advanced toolder side by one generation. In other words, frame change check resultsin frame change history record are shifted. In STATE A in FIG. 20, as anexample, five frame change check results starting from the newest,namely, 1, 1, 0, 0, 0, are shifted. As a result, a storage area for thenewest frame change check result in the frame change history recordbecomes “null” and older check results in the frame change historyrecord become 1, 1, 0, 0 (STATE B in FIG. 20). Moreover, the number offrame change check results in the history record is not required to befive.

In S305, a frame change check (single frame change check) is performedon a loaded newest frame and the result is added to the frame changehistory record as the newest frame change check result.

In S306, as a result of S305, a determination is made on whether or nota frame change has occurred. If “Yes”, the subroutine proceeds to S307.If “No”, the subroutine returns to S301.

In S307, the change flag of the newest frame change check result in theframe change history record stored in RAM 69 is set to ON. In STATE C inFIG. 20, as an example, an occurrence of a frame change is determinedfor the newest frame and the frame change history record becomes 1, 1,1, 0, 0.

S308 is the same as S4.

In S309 and S310, frame change check (total frame change check) isperformed based on the frame change history record. In S309, the framechange history record stored in the RAM 69 is referenced and the numberof frame changes occurred (E_AUTOSR_FRAME_CHECK_HISTORY) is counted.

In S310, it is determined whether or not the number of frame changeoccurrences (E_AUTOSR_FRAME_CHECK_HISTORY) counted in S309 among theprevious M (in FIG. 20, M=5) number of frame change check results isequal to or greater than a predetermined scene change determinationthreshold (E_AUTOSR_SCENE_CHANGE_JUDGE) stored in the ROM 68. If “Yes”,the main processing proceeds to S310. If “No”, the main processingreturns to S301.

In S310, it is determined that a scene change has occurred, whereby“status” is set to a search state and the frame change history record inthe RAM 69 is cleared. That is, the frame change history record 1, 1, 1,0, 0 shown in STATE C in FIG. 20 is all cleared and determination (totalframe change check) of occurrence/nonoccurrence of a scene change basedon the frame change history record is not performed until M number offrame change check results are newly accumulated.

In S311, a determination is made on whether or not the scene recognitionhistory record retaining flag is ON. If “Yes”, the main processingproceeds to S313. If “No”, the main processing proceeds to S312.

In S312, the scene recognition counter in the RAM 69 is set to 0, andthe scene recognition history record is cleared.

S5313 to S321 are respectively the same as S9 to S17.

In the present processing, a frame status when the previous scenerecognition result SR had been finalized and changes in the state of acurrent frame are monitored. A predetermined number of the frame changestates (single frame change check results) are to be sequentially storedfrom oldest to newest as a frame change history record. If the number ofdetermination results of “frame change occurred” in the history recordincluding E_AUTOSR_FRAME_CHECK_HISTORY number of results is equal to orgreater than E_AUTOSR_SCENE_CHANGE_JUDGE (“Yes” in S309), it isdetermined that “scene change occurred” is made (S310) and therecognizing section becomes operational (S313).

In this manner, by using the frame change history record when performinga scene change check, hunting can be prevented and accurate scene changecheck (determination) can be performed.

Fourth Embodiment

FIG. 21 is a flowchart of main processing (scene changerecognition/cyclic recognition concomitant) according to a fourthembodiment. This processing can be executed selectively with theprocessing shown in FIG. 2 (or FIG. 19). Execution of the processing iscontrolled by the CPU 75 of the digital camera 1. A program defining theprocessing is stored in the ROM 68.

S401 is the same as S1.

In S402, the frame change history records in the RAM 69 are initialized,the frame change reference information is initialized, “status” is setto a search state, the check counter is set to 0, and the scenerecognition history record retaining flag is set to OFF.

In S403, a determination is made on whether or not “status” is afinalized state. If “Yes”, the main processing proceeds to S404. If“No”, the main processing proceeds to S415.

In S404, a determination is made on whether or not a flag instructing tocause the recognizing section to become cyclically operational(E_AUTOSR_RECOGNIZE_CYCLE_TYPE=0) has been set. If “Yes”, the mainprocessing proceeds to S405. If “No”, the main processing proceeds toS412. The value of E_AUTOSR_RECOGNIZE_CYCLE_TYPE may either bearbitrarily inputted by the user via the manipulation section 11 or bestored in advance in the ROM 68 by the manufacturer. The cyclic unit isalso arbitrary and may be arbitrarily set by the user from themanipulation section 11. For example, a cycle can be set to “every twoseconds” or “every five frames”. By causing the recognizing section tooperate cyclically, recognition results can be prevented from changingrapidly and stability can be increased. In addition, since checks areperformed cyclically, even if an inappropriate recognition istemporarily made, such an inappropriate recognition does not remainoutputted subsequent to such a result.

S405 to S411 are respectively the same as S304 to S310.

In S412 to S414, “status” is set to a search state depending on theoccurrence/nonoccurrence of the arrival of a constant cycle in which ascene change search is performed. In other words, in S412, the checkcounter is incremented by 1, and in S413, a determination is made onwhether or not the check counter has reached a predetermined searchcycle E_AUTOSR_CONST_SEARCH_CYCLE stored in the ROM 68. If “Yes”, themain processing proceeds to S414. If “No”, the main processing returnsto S401. In S414, “status” is set to a search state and the checkcounter is set to 0.

S415 to S425 are respectively the same as S311 to S321.

A timing when the recognizing section becomes operational (that is,scene recognition is performed), may set at a point when scene change isdetected at a constant frequency, and both setting timings havedrawbacks and advantages. When the scene recognition is set to beperformed at a point when scene change is detected, responsiveness isincreased compared to when it is set at a constant frequency. Incontrast, in the case when scene recognition is set to be performed perconstant cycle, greater stability is achieved and even when an erroneousscene judgment is once made, such a judgment will not be outputted onthe screen. Accordingly, enabling the user to select which of themethods is to be adopted makes it possible to enhance user-specificusability.

In addition, even when the selection as to the timing is to be made inadvance by a designer (manufacture) instead of enabling user selection,it is possible to realize operations of both cases by taking advantageof parametric differences utilizing common firmware. Therefore, it iseven possible to change control according to users who are targets ofdifferent camera products (models) without changing firmware.

Fifth Embodiment

Next, a fifth embodiment of the present invention will be described.Hereinafter, descriptions of configurations similar to that of the firstembodiment shall be omitted.

The present embodiment is arranged such that the number of single scenerecognition results used to judge a scene SR during total scenerecognition during S1-on is reduced as compared to before S1 (duringS1-off or during live view display).

FIG. 22 is a flowchart showing total scene recognition processing(before S1) according to the fifth embodiment of the present invention.

First, photographic information on a face detection result, a focusinglens position, a zoom lens position, an in-focus state and a photometricvalue is acquired by the CPU 75, and scene recognition (single scenerecognition) is performed using the photographic information (stepST20).

Storage areas of scene recognition history record on the memory (RAM 69)are shifted to create a free area for storing the newest value of singlescene recognition result (step ST22). The newest single scenerecognition result in step ST20 is written into the storage area for thenewest value (step ST24).

A scene recognition history record including a predetermined number ofsingle scene recognition results (the number of results to be referencedfor before S1) used to judge a scene SR in the total scene recognitionbefore S1 (during live view display) are read (step ST26), and based onthe scene recognition history record, the current scene SR is judged(step ST28). For example, in the case where the number of the singlescene recognition results “a” to be referenced when the total scenerecognition before S1 is performed, is set as “a=5,” five single scenerecognition results are read out. Moreover, in step ST28, in the samemanner as in step ST18 described above, in the total scene recognition,the scene SR currently being photographed is judged based on, forexample, the number of recognitions (recognition frequency) and thenewness of the recognition results in the scene recognition historyrecord. A photographing mode is set in accordance with the judgmentresult of the scene SR.

FIG. 23 is a flowchart showing total scene recognition processing(during S1-on) according to the fifth embodiment of the presentinvention.

First, information on a face detection result, a focusing lens position,a zoom lens position, an in-focus state and a photometric value isacquired by the CPU 75, and scene recognition (single scene recognition)is performed using the information (step ST30).

A judgment is made on whether the scene recognition history record is tobe referenced (step ST32). When the scene recognition during S1-on isset so as not to reference the scene recognition history record (No instep ST32), the single scene recognition result in step ST30 is set asthe current scene (SR) (step ST34). When the scene recognition duringS1-on is set so as to reference the scene recognition history record(perform total scene recognition) (Yes in step ST32), storage areas ofthe scene recognition history record on the memory (RAM 69) are shiftedto create a free area for storing the newest value of the single scenerecognition result (step ST36). The newest single scene recognitionresult in step ST30 is written into the storage area for the newestvalue (step ST38).

Scene recognition history record including the number of single scenerecognition results to be referenced for after S1, the number is smallerthan the number of single scene recognition results to be referenced forbefore S1, is read (step ST40). Then, based on the scene recognitionhistory record, the current scene SR is judged (step ST42). For example,in the case where the number of the single scene recognition results “a”to be referenced when the total scene recognition before S1 isperformed, is set as “a=5,” the number of the single scene recognitionresults “b” to be referenced when the total scene recognition after S1is performed, can be set as “b=4.” In this case, four single scenerecognition results are read out. Moreover, in step ST42, in the samemanner as in step S18 described above, in total scene recognition, thescene SR currently being photographed is judged based on, for example,the number of recognitions (recognition frequency) and the newness ofthe recognition result in the scene recognition history record. Aphotographing mode is set in accordance with the judgment result of thescene SR.

Generally, photographic information obtained by S1 AE and S1 AF(hereinafter referred to as S1 AUTO) is more accurate than photographicinformation obtained by CAE and CAF (hereinafter referred to as CAUTO).Therefore, it is assumed that a single scene recognition result based onphotographic information during S1 AUTO is more accurate than a singlescene recognition result based on that during CAUTO. In the presentembodiment, by reducing the number of single scene recognition resultsused to judge a scene SR in total scene recognition during S1-on incomparison to before S1 (during live view display), the number of singlescene recognition results before S1 in scene recognition history recordto be referenced in total scene recognition during S1-on can be loweredand the influence thereof can be reduced.

According to the present embodiment, by reducing the number of singlescene recognition results in history record used to judge a scene SR intotal scene recognition during S1-on in comparison to before S1 (duringlive view display), it is now possible to achieve both stability oftotal scene recognition results before S1 and accuracy of total scenerecognition results during S1-on.

Moreover, when placing emphasis on accuracy, it is also possible toarrange the total scene recognition during S1-on so that history recordon single scene recognition results before S1 is not referenced.

Sixth Embodiment

Next, a sixth embodiment of the present invention will be described.Hereinafter, descriptions of configurations similar to that of the firstembodiment shall be omitted.

In the present embodiment, total scene recognition is arranged so as toperform weighting when aggregating scene recognition history record suchthat a greater weight is assigned to a newer single scene recognitionresult (the newer the single scene recognition is, the greater theweight is assigned).

FIGS. 24A and 24B are diagrams schematically showing total scenerecognition processing (before S1) according to the sixth embodiment ofthe present invention.

In the same manner as the first and fifth embodiments described above,as shown in FIG. 24A, during live view display before S1, single scenerecognition results before S1 are sequentially stored as scenerecognition history record in predetermined storage areas A[0], A[1],A[2], . . . of the RAM 69.

When a scene recognition history record is updated, the CPU 75 reads outand aggregates single scene recognition results from the scenerecognition history record to perform total scene recognition. As shownin FIG. 24A, the digital camera 1 according to the present embodimentstores in advance in the RAM 69 weights w[i] (where i=0, 1, 2, . . . )to be assigned to individual single scene recognition results in thescene recognition history record. The value of the weight w[i] is set sothat the older the scene recognition history record is, the smaller thevalue becomes. The CPU 75 performs multiplication by weight w[i] whenaggregating single scene recognition results to calculate a score foreach scene, and the scene with the highest score is judged to be thecurrent scene (SR).

In the example shown in FIG. 24A, the scores of the respective scenesare as follows, as shown FIGS. 24A and 24B.

$\begin{matrix}{{{Score}( {{ID} = 1} )} = {{1 \times {w\lbrack 1\rbrack}} + {1 \times {w\lbrack 2\rbrack}} + {1 \times {w\lbrack 3\rbrack}} + {1 \times {w\lbrack 4\rbrack}}}} \\{= {3 + 2 + 1 + 1}} \\{= 7}\end{matrix}$ $\begin{matrix}{{{Score}( {{ID} = 3} )} = {1 \times {w\lbrack 0\rbrack}}} \\{= 5}\end{matrix}$

Therefore, a scene ID indicating the total scene recognition result isSR=1 and the photographing mode is set to the “portrait” mode.

FIGS. 25A and 25B are diagrams schematically showing total scenerecognition processing (during S1-on) according to the sixth embodimentof the present invention.

In the example shown in FIG. 25A, the weight assigned to the scenerecognition results in the history record after S1 is maximized and thescores of the respective scenes are as follows, as shown in FIG. 25B.

$\begin{matrix}{{{Score}( {{ID} = 0} )} = {{1 \times {w\lbrack 2\rbrack}} + {1 \times {w\lbrack 3\rbrack}} + {1 \times {w\lbrack 4\rbrack}}}} \\{= {2 + 1 + 1}} \\{= 4}\end{matrix}$ $\begin{matrix}{{{Score}( {{ID} = 1} )} = {1 \times {w\lbrack 1\rbrack}}} \\{= 5}\end{matrix}$ $\begin{matrix}{{{Score}( {{ID} = 3} )} = {1 \times {w\lbrack 0\rbrack}}} \\{= 10}\end{matrix}$

Therefore, a scene ID indicating the total scene recognition result isSR=3 and the photographing mode is set to the “night scene” mode.

Moreover, it is also possible to arrange only results after S1 to beused by assigning weights with values greater than 0 to be applied tosingle scene recognition results during S1-on and setting all weightsbefore S1 to 0.

While the present embodiment is arranged so that values of weightsdiffer between before S1 and during S1-on (after S1-on), the same valuesmay be used instead.

FIG. 26 is a flowchart showing total scene recognition processing(before S1) according to the sixth embodiment of the present invention.

First, information on a face detection result, a focusing lens position,a zoom lens position, an in-focus state and a photometric value isacquired by the CPU 75, and scene recognition (single scene recognition)is performed using the information (step ST50).

Storage areas of scene recognition history record on the memory (RAM 69)are shifted to create a free area for storing the newest value of singlescene recognition result (step ST52). The newest scene recognitionresult in step ST50 is written into the storage area for the newestvalue (step ST54).

Scene recognition history record including the number of single scenerecognition results (the number of results to be referenced for beforeS1) used to judge a scene SR in the total scene recognition before S1(during live view display) are read (step ST56) and weighting isexecuted (step ST58). Based on the weighted scene recognition historyrecord, the current scene SR is judged (step ST60). Moreover, in stepST60, in the same manner as in step ST18 described above, in total scenerecognition, the scene SR currently being photographed is judged basedon, for example, the number of recognitions (recognition frequency) andthe newness of the recognition result in the scene recognition historyrecord. A photographing mode is set in accordance with the judgmentresult of the scene SR.

FIG. 27 is a flowchart showing total scene recognition processing(during S1-on) according to the sixth embodiment of the presentinvention.

First, information on a face detection result, a focusing lens position,a zoom lens position, an in-focus state and a photometric value isacquired by the CPU 75, and scene recognition (single scene recognition)is performed using the information (step ST70).

A judgment is made on whether the scene recognition history record is tobe referenced (step ST72). When the scene recognition during S1-on isset so as not to reference scene recognition history record (No in stepST72), the single scene recognition result in step ST70 is set as thecurrent scene (SR) (step ST74).

When the scene recognition during S1-on is set so as to reference scenerecognition history record (perform total scene recognition) (Yes instep ST72), storage areas of the scene recognition history record on thememory (RAM 69) are shifted to create a free area for storing the newestvalue of the scene recognition result (step ST76). The newest scenerecognition result in step ST70 is written into the storage area for thenewest value (step ST78).

Scene recognition history record including the number of single scenerecognition results to be referenced for after S1 which is smaller thanthe number of single scene recognition results to be referenced forbefore S1 is read (step ST80) and weighting is executed (step ST82).Based on the scene recognition history record, the current scene SR isjudged (step ST84). Moreover, in step ST84, in the same manner as instep ST18 described above, the scene SR currently being photographed isjudged based on, for example, the number of recognitions (recognitionfrequency) and the newness of the recognition result in the scenerecognition history record. A photographing mode is set in accordancewith the judgment result of the scene SR.

According to the present embodiment, by weighting single scenerecognition results when aggregating scene recognition history recordsuch that the newer the single scene recognition result is, the greaterthe weight is assigned, responsiveness in the event of an occurrence ofa scene change can be improved, and both stability and responsiveness ofscene recognition results can be achieved. In addition, since singlescene recognition results based on photographic information during S1AUTO have a high degree of accuracy, it is now possible to improve scenerecognition accuracy by increasing the weight assigned to single scenerecognition results during S1-on.

Seventh Embodiment

Next, a seventh embodiment of the present invention will be described.Hereinafter, descriptions of configurations similar to that of the firstembodiment shall be omitted.

The present embodiment involves storing history record of photographicinformation (information on photographic scene, for example, at leastone of a face detection result, a focusing lens position, a zoom lensposition, an in-focus state and a photometric value) to be used in scenerecognition in the RAM 69, calculating representative values of therespective types of photographic information from the photographicinformation history record, and performing total scene recognition basedon the representative values.

FIG. 28 is a diagram schematically showing total scene recognitionprocessing according to the seventh embodiment of the present invention.

In the same manner as the first embodiment described above, the digitalcamera 1 according to the present embodiment performs continuous AE(CAE) and continuous AF (CAF) during the photographing mode. Inaddition, when the shutter button is pressed halfway (during S1-on), S1AE and S1 AF are performed. As shown in FIG. 28, photographicinformation obtained by CAE and CAF, and S1 AE and S1 AF, issequentially stored in the RAM 69.

While brightness EV[i] (photometric value or EV value) and subjectdistance POS[i] (e.g., focusing lens position) are presented as examplesas photographic information in the example shown in FIG. 28, otherinformation (such as face detection results (presence/absence of face,number of faces), zoom lens position, and photometric value) may bestored instead.

The CPU 75 reads out the photographic information history record andcalculates representative values of the respective types of photographicinformation at each predetermined time interval. For example,photographic information can be read out whenever new photographicinformation is stored in the RAM 69 by CAE to update CAF and thephotographic information in the RAM 69, or whenever a predeterminednumber of photographic information is stored in the history record). TheCPU 75 performs total scene recognition based on the representativevalues. In this case, for example, an average value or a median valuecan be used as the representative value of photographic information. Inaddition, as the representative value, for example, it is also possibleto use an average value calculated by arranging values of photographicinformation in a descending order of size, excluding N number of unitsof photographic information from the maximum value-size side and Mnumber of units of photographic information from the minimum value-sizeside (where both N=M and N≠M are permissible), and calculating anaverage value on the remaining units of photographic information. Inthis case, since values extremely distanced from other photographicinformation can be excluded, the effects of scene change or noise can bemitigated.

FIG. 29 is a flowchart showing total scene recognition processingaccording to the seventh embodiment of the present invention. Theprocessing shown in FIG. 29 is executed during the photographing mode ateach predetermined time interval. For example, the processing can beexecuted whenever new photographic information is stored in the RAM 69by CAE and CAF to update the photographic information in the RAM 69, orwhenever a predetermined number of photographic information is stored inthe history record).

A photographic information history record (for example, brightness andsubject distance) is read from the RAM 69 (step ST90), andrepresentative values thereof (EVa, POSa) are calculated (step ST92).

Total scene recognition is performed based on the representative values(EVa, POSa) (step ST94) and a photographing mode is set in accordancewith the total scene recognition result.

According to the present embodiment, by chronologically storingphotographic information for scene recognition obtained during AE andAF, and performing scene recognition using photographic informationhistory record, it is now possible to acquire a stable scene recognitionresult.

Eighth Embodiment

Next, an eighth embodiment of the present invention will be described.Hereinafter, descriptions of configurations similar to that of the firstembodiment shall be omitted.

FIG. 30 is a diagram schematically showing total scene recognitionprocessing (before S1) according to the eighth embodiment of the presentinvention, and FIG. 31 is a diagram schematically showing total scenerecognition processing (during S1-on) according to the eighth embodimentof the present invention. As shown in FIG. 30 and FIG. 31, the presentembodiment is arranged such that the number of photographic informationin photographic information history record to be used in total scenerecognition during S1-on is reduced as compared to before S1 (duringlive view display).

FIG. 32 is a flowchart showing total scene recognition processing(before S1) according to the eighth embodiment of the present invention.The processing shown in FIG. 32 is executed during the photographingmode at each predetermined time interval. For example, the processingcan be executed whenever new photographic information is stored in theRAM 69 by CAE and CAF to update the photographic information in the RAM69, or whenever a predetermined number of photographic information isstored in the history record).

A photographic information history record including a predeterminednumber (corresponding to a number of units of photographic informationto be referenced for before S1) of units of photographic information(for example, brightness and subject distance) is read from the RAM 69(step ST100), and representative values thereof (EVa, POSa) arecalculated (step ST102).

Total scene recognition is performed based on the representative values(EVa, POSa) (step ST104) and a photographing mode is set in accordancewith the total scene recognition result.

FIG. 33 is a flowchart showing total scene recognition processing(during S1-on) according to the eighth embodiment of the presentinvention. The processing shown in FIG. 33 is executed after S1-on ateach predetermined time interval. For example, the processing can beperformed whenever new photographic information is stored in the RAM 69by CAE and CAF to update the photographic information in the RAM 69, orwhenever a predetermined number of photographic information is stored inhistory record).

A photographic information history record including a predeterminednumber of units of photographic information (for example, brightness andsubject distance) (a number of units of photographic information to bereferenced for after S1) which is smaller than the number of units ofphotographic information to be referenced for before S1 is read from theRAM 69 (step ST110), and representative values thereof (EVa, POSa) arecalculated (step ST112).

Total scene recognition is performed based on the representative values(EVa, POSa) (step ST114) and a photographing mode is set in accordancewith the total scene recognition result.

Generally, photographic information obtained through S1 AUTO is moreaccurate than photographic information obtained through CAUTO. In thepresent embodiment, the number of units of photographic information inthe history record to be used in total scene recognition during S1-on isreduced in comparison to the number of units of photographic informationto be used in total scene recognition before S1 (during live viewdisplay). Thus, the number of units of photographic information beforeS1 in scene recognition history record to be referenced in total scenerecognition during S1-on can be lowered and the influence thereof can bereduced. Accordingly, it is now possible to achieve both stability oftotal scene recognition results before S1 and accuracy of total scenerecognition results during S1-on.

Ninth Embodiment

Next, a ninth embodiment of the present invention will be described.Hereinafter, descriptions of configurations similar to that of the firstembodiment shall be omitted.

The present embodiment involves performing weighting when calculatingrepresentative values of photographic information such that the value ofa weight assigned to new photographic information is increased.

FIG. 34 is a diagram schematically showing total scene recognitionprocessing (before S1) according to the ninth embodiment of the presentinvention, and FIG. 35 is a diagram schematically showing total scenerecognition processing (during S1-on) according to the ninth embodimentof the present invention.

As shown in FIG. 34 and FIG. 35, the digital camera 1 according to thepresent embodiment stores in advance in the RAM 69 weights w[i] (wherei=0, 1, 2, . . . ) to be assigned when aggregating photographicinformation. The value of the weight w[i] is set so that the older thephotographic information in the history record is, the smaller the valueis assigned. Moreover, the value of the weight w[i] may differ betweenbefore S1 and during S1-on, or may be the same.

FIG. 36 is a flowchart showing total scene recognition processing(before S1) according to the ninth embodiment of the present invention.The processing shown in FIG. 36 is executed during the photographingmode at each predetermined time interval. For example, the processingcan be executed whenever new photographic information is stored in theRAM 69 by CAE and CAF to update the photographic information in the RAM69, or whenever a predetermined number of photographic information isstored in the history record.

A photographic information history record including a predeterminednumber (corresponding to the number to be referenced for before S1) ofunits of photographic information (for example, brightness and subjectdistance) is read from the RAM 69 (step ST120), each of the photographicinformation is weighted (step ST122), and representative values(weighted average values) EVa and POSa thereof are calculated (stepST124).

Total scene recognition is performed based on the representative values(EVa, POSa) (step ST126) and a photographing mode is set in accordancewith the total scene recognition result.

FIG. 37 is a flowchart showing total scene recognition processing(during S1-on) according to the ninth embodiment of the presentinvention. The processing shown in FIG. 37 is executed after S1-on ateach predetermined time interval. For example, the processing can beexecuted whenever new photographic information is stored in the RAM 69by CAE and CAF to update the photographic information in the RAM 69, orwhenever a predetermined number of photographic information is stored inhistory record.

A photographic information history record including a predeterminednumber of units of photographic information (for example, brightness andsubject distance), the number of units of photographic information to bereferenced for after S1 which is smaller than the number of units ofphotographic information to be referenced for before S1 is read from theRAM 69 (step ST130), each of the photographic information is weighted(step ST132), and representative values (weighted average values) EVaand POSa thereof are calculated (step ST134).

Total scene recognition is performed based on the representative values(EVa, POSa) (step ST136) and a photographing mode is set in accordancewith the total scene recognition result.

According to the present embodiment, by performing weighting perphotographic information when calculating representative values ofphotographic information, responsiveness in the event of an occurrenceof a scene change can be improved, and both stability and responsivenessof scene recognition results can be achieved. In addition, sincephotographic information obtained during S1 AUTO has a high degree ofaccuracy, it is now possible to improve scene recognition accuracy byincreasing the weight assigned to photographic information during S1-on.

1. An imaging apparatus comprising: an information acquiring deviceconfigured to acquire photographic information which is information on aphotographic scene from an image; a reference information registeringdevice configured to register reference information which is set basedon the photographic information; a scene change determining deviceconfigured to determine whether or not the scene has changed based onthe reference information stored in the reference informationregistering device and current photographic information acquired from acurrent image by the information acquiring device; a scene recognizingdevice configured to perform a scene recognition processing to recognizea scene based the current photographic information acquired from thecurrent image by the information acquiring device when it is determined,by the scene change determining device, that a scene is changed; and acontrol device configured to perform at least one of display control,photographic control, signal processing control, and informationrecording control in response to the result of the scene recognitionprocessing by the scene recognizing device.
 2. The imaging apparatusaccording to claim 1, wherein the scene recognition device updates thereference information registered in the reference informationregistering device based on the current photographic informationcorresponding to the result of the scene recognition processing.
 3. Theimaging apparatus according to claim 1, wherein the informationacquiring device acquires at least one of: face detection resultinformation indicating whether a human face exists in the photographicscene; subject distance information on a subject distance; andphotometric information on brightness of a subject.
 4. The imagingapparatus according to claim 1, wherein the information acquiring deviceacquires, as the photographic information, two or more of: facedetection result information indicating whether a human face exists in aphotographic scene; subject distance information on a subject distance;and photometric information on brightness of a subject, and the scenechange determining device determines whether the photographic scene haschanged or not based on the current photographic information acquired bythe information acquiring device and the reference information stored inthe reference information registering device, the reference informationcorresponding to the photographic information.
 5. The imaging apparatusaccording to claim 4, wherein the scene change determining deviceincludes a weight setting device which respectively weights, byinformation type, the two or more of information acquired by theinformation acquiring device and the reference information stored in thereference information registering device, the reference informationcorresponding to the two or more of information.
 6. The imagingapparatus according to claim 1, further comprising a photographicinformation history record registering device configured to register, asa photographic information history record, a history of the photographicinformation acquired by the information acquiring device, wherein thescene recognizing device comprises a total scene recognizing devicewhich performs total scene recognition for recognizing the photographicscene based on the photographic information history record registered inthe photographic information history record registering device.
 7. Theimaging apparatus according to claim 6, wherein the scene recognitiondevice updates the reference information registered in the referenceinformation registering device based on a result of the total scenerecognition.
 8. The imaging apparatus according to claim 6, wherein thetotal scene recognizing device comprising: a calculation deviceconfigured to calculate representative values from the photographicinformation history record registered in the photographic informationhistory record registering device; and a recognizing device configuredto perform a total scene recognition to recognize the scene based on therepresentative values calculated by the calculation device.
 9. Theimaging apparatus according to claim 6, further comprising a shutterbutton configured to instruct photo-metering and ranging for primaryexposure when halfway pressed and to instruct primary exposure whenfully pressed, wherein a number of the history of the photographicinformation to be used in total scene recognition during the shutterbutton is halfway pressed is reduced as compared to that before theshutter button is halfway pressed.
 10. The imaging apparatus accordingto claim 1, further comprising a photographing mode setting deviceconfigured to set a photographing mode depending on the result of thescene recognition processing by the scene recognizing device, whereinthe control device performs the photographic control according to theset photographing mode.
 11. The imaging apparatus according to claim 1,further comprising a shutter button configured to instructphoto-metering and ranging for primary exposure when halfway pressed andinstructs primary exposure when fully pressed, wherein after the shutterbutton is pressed halfway, the information acquiring device acquiresonly information indicating a subject distance for primary exposure andinformation on the brightness of a subject for primary exposure.
 12. Theimaging apparatus according to claim 1, further comprising: a selectingdevice configured to select a timing to perform scene recognition of thephotographic scene from upon a determination of scene change or at apredetermined cycle; and a cycle setting device configured to set thepredetermined cycle when the scene recognition is to be performed,wherein when the selecting device selects to perform the scenerecognition of the photographic scene at the predetermined cycle, thescene recognizing device performs the scene recognition of thephotographic scene based on the photographic information acquired by theinformation acquiring device at the predetermined cycle set by the cyclesetting device instead of upon the determination of scene change by thescene change determining device.
 13. The imaging apparatus according toclaim 12, wherein the predetermined cycle to be set by the cycle settingdevice is a preset cycle or a cycle arbitrarily settable by a user. 14.An imaging method comprising: acquiring photographic information whichis information on a photographic scene from an image; recognizing ascene from the acquired photographic information; storing referenceinformation which is set based on the photographic informationcorresponding to the scene recognition result; determining whether thescene has changed or not from based on the stored reference informationand the current photographic information acquired from a current image;performing a scene recognition processing to recognize the scene basedon the current photographic information when it is determined that thescene has changed; and performing at least one of display control,photographic control, signal processing control, and informationrecording control in response to the result of the scene recognitionprocessing.
 15. The imaging method according to claim 14, wherein therecognizing of a scene includes: a photographic information historyrecord registering step for registering a predetermined number of newestunits of photographic information as photographic history record in aphotographic information history record registering device; and a totalscene recognizing step for recognizing the photographic scene based onthe photographic information history record registered in thephotographic information history record registering device.
 16. Theimaging method according to claim 14, further comprising updating thereference information registered in the reference informationregistering device based on the current photographic informationcorresponding to the result of the scene recognition processing.